xref: /netbsd/sys/dev/ic/z8530reg.h (revision 6a7344ab)
1 /*	$NetBSD: z8530reg.h,v 1.13 2022/05/24 20:50:19 andvar Exp $ */
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This software was developed by the Computer Systems Engineering group
8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9  * contributed to Berkeley.
10  *
11  * All advertising materials mentioning features or use of this software
12  * must display the following acknowledgement:
13  *	This product includes software developed by the University of
14  *	California, Lawrence Berkeley Laboratory.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  * 3. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  *	@(#)zsreg.h	8.1 (Berkeley) 6/11/93
41  */
42 
43 /*
44  * Zilog SCC registers, as implemented on the Sun-4c.
45  *
46  * Each Z8530 implements two channels (called `a' and `b').
47  *
48  * The damnable chip was designed to fit on Z80 I/O ports, and thus
49  * has everything multiplexed out the wazoo.  We have to select
50  * a register, then read or write the register, and so on.  Worse,
51  * the parameter bits are scattered all over the register space.
52  * This thing is full of `miscellaneous' control registers.
53  *
54  * Worse yet, the registers have incompatible functions on read
55  * and write operations.  We describe the registers below according
56  * to whether they are `read registers' (RR) or `write registers' (WR).
57  * As if this were not enough, some of the channel B status bits show
58  * up in channel A, and vice versa.  The blasted thing shares write
59  * registers 2 and 9 across both channels, and reads registers 2 and 3
60  * differently for the two channels.  We can, however, ignore this much
61  * of the time.
62  *
63  * This file also includes flags for the Z85C30 and Z85230 enhanced scc.
64  * The CMOS 8530 includes extra SDLC functionality, and is used in a
65  * number of Macs (often in the Z85C80, an 85C30 combined w/ a SCSI
66  * controller). -wrs
67  *
68  * Some of the names in this files were chosen to make the hsis driver
69  * work unchanged (which means that they will match some in SunOS).
70  *
71  * `S.C.' stands for Special Condition, which is any of these:
72  *	receiver overrun	(aka silo overflow)
73  *	framing error		(missing stop bit, etc)
74  *	end of frame		(in synchronous modes)
75  *	parity error		(when `parity error is S.C.' is set)
76  *
77  * Registers with only a single `numeric value' get a name.
78  * Other registers hold bits and are only numbered; the bit
79  * definitions imply the register number (see below).
80  *
81  * We never use the receive and transmit data registers as
82  * indirects (choosing instead the zc_data register), so they
83  * are not defined here.
84  */
85 #define	ZSRR_IVEC	2	/* interrupt vector (channel 0) */
86 #define	ZSRR_IPEND	3	/* interrupt pending (ch. 0 only) */
87 #define	ZSRR_TXSYNC	6	/* sync transmit char (monosync mode) */
88 #define	ZSRR_RXSYNC	7	/* sync receive char (monosync mode) */
89 #define	ZSRR_SYNCLO	6	/* sync low byte (bisync mode) */
90 #define	ZSRR_SYNCHI	7	/* sync high byte (bisync mode) */
91 #define	ZSRR_SDLC_ADDR	6	/* SDLC address (SDLC mode) */
92 #define	ZSRR_SDLC_FLAG	7	/* SDLC flag 0x7E (SDLC mode) */
93 #define	ZSRR_BAUDLO	12	/* baud rate generator (low half) */
94 #define	ZSRR_BAUDHI	13	/* baud rate generator (high half) */
95 #define	ZSRR_ENHANCED	14	/* read address of WR7' - yes, it's not 7!*/
96 
97 #define	ZSWR_IVEC	2	/* interrupt vector (shared) */
98 #define	ZSWR_TXSYNC	6	/* sync transmit char (monosync mode) */
99 #define	ZSWR_RXSYNC	7	/* sync receive char (monosync mode) */
100 #define	ZSWR_SYNCLO	6	/* sync low byte (bisync mode) */
101 #define	ZSWR_SYNCHI	7	/* sync high byte (bisync mode) */
102 #define	ZSWR_SDLC_ADDR	6	/* SDLC address (SDLC mode) */
103 #define	ZSWR_SDLC_FLAG	7	/* SDLC flag 0x7E (SDLC mode) */
104 #define	ZSWR_BAUDLO	12	/* baud rate generator (low half) */
105 #define	ZSWR_BAUDHI	13	/* baud rate generator (high half) */
106 #define	ZSWR_ENHANCED	7	/* write address of WR7' */
107 
108 /*
109  * Registers 0 through 7 may be written with any one of the 8 command
110  * modifiers, and/or any one of the 4 reset modifiers, defined below.
111  * To write registers 8 through 15, however, the command modifier must
112  * always be `point high'.  Rather than track this bizzareness all over
113  * the driver, we try to avoid using any modifiers, ever (but they are
114  * defined here if you want them).
115  */
116 #define	ZSM_RESET_TXUEOM	0xc0	/* reset xmit underrun / eom latch */
117 #define	ZSM_RESET_TXCRC		0x80	/* reset xmit crc generator */
118 #define	ZSM_RESET_RXCRC		0x40	/* reset recv crc checker */
119 #define	ZSM_NULL		0x00	/* nothing special */
120 
121 #define	ZSM_RESET_IUS		0x38	/* reset interrupt under service */
122 #define	ZSM_RESET_ERR		0x30	/* reset error cond */
123 #define	ZSM_RESET_TXINT		0x28	/* reset xmit interrupt pending */
124 #define	ZSM_EI_NEXTRXC		0x20	/* enable int. on next rcvd char */
125 #define	ZSM_SEND_ABORT		0x18	/* send abort (SDLC) */
126 #define	ZSM_RESET_STINT		0x10	/* reset external/status interrupt */
127 #define	ZSM_POINTHIGH		0x08	/* `point high' (use r8-r15) */
128 #define	ZSM_NULL		0x00	/* nothing special */
129 
130 /*
131  * Commands for Write Register 0 (`Command Register').
132  * These are just the command modifiers or'ed with register number 0
133  * (which of course equals the command modifier).
134  */
135 #define	ZSWR0_RESET_EOM		ZSM_RESET_TXUEOM
136 #define	ZSWR0_RESET_TXCRC	ZSM_RESET_TXCRC
137 #define	ZSWR0_RESET_RXCRC	ZSM_RESET_RXCRC
138 #define	ZSWR0_CLR_INTR		ZSM_RESET_IUS
139 #define	ZSWR0_RESET_ERRORS	ZSM_RESET_ERR
140 #define	ZSWR0_EI_NEXTRXC	ZSM_EI_NEXTRXC
141 #define	ZSWR0_SEND_ABORT	ZSM_SEND_ABORT
142 #define	ZSWR0_RESET_STATUS	ZSM_RESET_STINT
143 #define	ZSWR0_RESET_TXINT	ZSM_RESET_TXINT
144 
145 /*
146  * Bits in Write Register 1 (`Transmit/Receive Interrupt and Data
147  * Transfer Mode Definition').  Note that bits 3 and 4 are taken together
148  * as a single unit, and bits 5 and 6 are useful only if bit 7 is set.
149  */
150 #define	ZSWR1_REQ_WAIT		0x80	/* WAIT*-REQ* pin gives WAIT* */
151 #define	ZSWR1_REQ_REQ		0xc0	/* WAIT*-REQ* pin gives REQ* */
152 #define	ZSWR1_REQ_TX		0x00	/* WAIT*-REQ* pin follows xmit buf */
153 #define	ZSWR1_REQ_RX		0x20	/* WAIT*-REQ* pin follows recv buf */
154 
155 #define	ZSWR1_RIE_NONE		0x00	/* disable rxint entirely */
156 #define	ZSWR1_RIE_FIRST		0x08	/* rxint on first char & on S.C. */
157 #define	ZSWR1_RIE		0x10	/* rxint per char & on S.C. */
158 #define	ZSWR1_RIE_SPECIAL_ONLY	0x18	/* rxint on S.C. only */
159 
160 #define	ZSWR1_PE_SC		0x04	/* parity error is special condition */
161 #define	ZSWR1_TIE		0x02	/* transmit interrupt enable */
162 #define	ZSWR1_SIE		0x01	/* external/status interrupt enable */
163 
164 #define	ZSWR1_IMASK 	0x1F	/* mask of all itr. enable bits. */
165 
166 /* HSIS compat */
167 #define	ZSWR1_REQ_ENABLE	(ZSWR1_REQ_WAIT | ZSWR1_REQ_TX)
168 
169 /*
170  * Bits in Write Register 3 (`Receive Parameters and Control').
171  * Bits 7 and 6 are taken as a unit.  Note that the receive bits
172  * per character ordering is insane.
173  *
174  * Here `hardware flow control' means CTS enables the transmitter
175  * and DCD enables the receiver.  The latter is neither interesting
176  * nor useful, and gets in our way, making it almost unusable.
177  */
178 #define	ZSWR3_RX_5		0x00	/* receive 5 bits per char */
179 #define	ZSWR3_RX_7		0x40	/* receive 7 bits per char */
180 #define	ZSWR3_RX_6		0x80	/* receive 6 bits per char */
181 #define	ZSWR3_RX_8		0xc0	/* receive 8 bits per char */
182 #define	ZSWR3_RXSIZE		0xc0	/* receive char size mask */
183 
184 #define	ZSWR3_HFC		0x20	/* hardware flow control */
185 #define	ZSWR3_HUNT		0x10	/* enter hunt mode */
186 #define	ZSWR3_RXCRC_ENABLE	0x08	/* enable recv crc calculation */
187 #define	ZSWR3_ADDR_SEARCH_MODE	0x04	/* address search mode (SDLC only) */
188 #define	ZSWR3_SDLC_SHORT_ADDR	0x02	/* short address mode (SDLC only) */
189 #define	ZSWR3_SYNC_LOAD_INH	0x02	/* sync character load inhibit */
190 #define	ZSWR3_RX_ENABLE		0x01	/* receiver enable */
191 
192 /*
193  * Bits in Write Register 4 (`Transmit/Receive Miscellaneous Parameters
194  * and Modes').  Bits 7&6, 5&4, and 3&2 are taken as units.
195  */
196 #define	ZSWR4_CLK_X1		0x00	/* clock divisor = 1 */
197 #define	ZSWR4_CLK_X16		0x40	/* clock divisor = 16 */
198 #define	ZSWR4_CLK_X32		0x80	/* clock divisor = 32 */
199 #define	ZSWR4_CLK_X64		0xc0	/* clock divisor = 64 */
200 #define	ZSWR4_CLK_MASK		0xc0	/* clock divisor mask */
201 
202 #define	ZSWR4_MONOSYNC		0x00	/* 8 bit sync char (sync only) */
203 #define	ZSWR4_BISYNC		0x10	/* 16 bit sync char (sync only) */
204 #define	ZSWR4_SDLC  		0x20	/* SDLC mode */
205 #define	ZSWR4_EXTSYNC		0x30	/* external sync mode */
206 #define	ZSWR4_SYNC_MASK		0x30	/* sync mode bit mask */
207 
208 #define	ZSWR4_SYNCMODE		0x00	/* no stop bit (sync mode only) */
209 #define	ZSWR4_ONESB 		0x04	/* 1 stop bit */
210 #define	ZSWR4_1P5SB 		0x08	/* 1.5 stop bits (clk cannot be 1x) */
211 #define	ZSWR4_TWOSB 		0x0c	/* 2 stop bits */
212 #define	ZSWR4_SBMASK		0x0c	/* mask of all stop bits */
213 
214 #define	ZSWR4_EVENP 		0x02	/* check for even parity */
215 #define	ZSWR4_PARENB		0x01	/* enable parity checking */
216 #define	ZSWR4_PARMASK		0x03	/* mask of all parity bits */
217 
218 /*
219  * Bits in Write Register 5 (`Transmit Parameter and Controls').
220  * Bits 6 and 5 are taken as a unit; the ordering is, as with RX
221  * bits per char, not sensible.
222  */
223 #define	ZSWR5_DTR		0x80	/* assert (set to -12V) DTR */
224 
225 #define	ZSWR5_TX_5		0x00	/* transmit 5 or fewer bits */
226 #define	ZSWR5_TX_7		0x20	/* transmit 7 bits */
227 #define	ZSWR5_TX_6		0x40	/* transmit 6 bits */
228 #define	ZSWR5_TX_8		0x60	/* transmit 8 bits */
229 #define	ZSWR5_TXSIZE		0x60	/* transmit char size mask */
230 
231 #define	ZSWR5_BREAK		0x10	/* send break (continuous 0s) */
232 #define	ZSWR5_TX_ENABLE		0x08	/* enable transmitter */
233 #define	ZSWR5_CRC16		0x04	/* use CRC16 (off => use SDLC) */
234 #define	ZSWR5_RTS		0x02	/* assert RTS */
235 #define	ZSWR5_TXCRC_ENABLE	0x01	/* enable xmit crc calculation */
236 
237 #ifdef not_done_here
238 /*
239  * Bits in Write Register 7 when the chip is in SDLC mode.
240  */
241 #define	ZSWR7_SDLCFLAG		0x7e	/* this value makes SDLC mode work */
242 #endif
243 
244 /*
245  * Bits in Write Register 7' (ZSWR_ENHANCED above). This register is
246  * only available on the 85230. Despite the fact it contains flags
247  * and not a single value, the register was named as it is read
248  * via RR14. Weird.
249  */
250 			/*	0x80	unused */
251 #define	ZSWR7P_EXTEND_READ	0x40	/* modify read map; make most regs readable */
252 #define	ZSWR7P_TX_FIFO		0x20	/* change level for Tx FIFO empty int */
253 #define	ZSWR7P_DTR_TIME		0x10	/* modifies deact. speed of /DTR//REQ */
254 #define	ZSWR7P_RX_FIFO		0x08	/* Rx FIFO int on 1/2 full? */
255 #define	ZSWR7P_RTS_DEACT	0x04	/* automatically deassert RTS */
256 #define	ZSWR7P_AUTO_EOM_RESET	0x02	/* automatically reset EMO/Tx Underrun */
257 #define	ZSWR7P_AUTO_TX_FLAG	0x01	/* Auto send SDLC flag at transmit start */
258 
259 /*
260  * Bits in Write Register 9 (`Master Interrupt Control').  Bits 7 & 6
261  * are taken as a unit and indicate the type of reset; 00 means no reset
262  * (and is not defined here).
263  */
264 #define	ZSWR9_HARD_RESET	0xc0	/* force hardware reset */
265 #define	ZSWR9_A_RESET		0x80	/* reset channel A (0) */
266 #define	ZSWR9_B_RESET		0x40	/* reset channel B (1) */
267 #define	ZSWR9_SOFT_INTAC	0x20	/* Not in NMOS version */
268 
269 #define	ZSWR9_STATUS_HIGH	0x10	/* status in high bits of intr vec */
270 #define	ZSWR9_MASTER_IE		0x08	/* master interrupt enable */
271 #define	ZSWR9_DLC		0x04	/* disable lower chain */
272 #define	ZSWR9_NO_VECTOR		0x02	/* no vector */
273 #define	ZSWR9_VECTOR_INCL_STAT	0x01	/* vector includes status */
274 
275 /*
276  * Bits in Write Register 10 (`Miscellaneous Transmitter/Receiver Control
277  * Bits').  Bits 6 & 5 are taken as a unit, and some of the bits are
278  * meaningful only in certain modes.  Bleah.
279  */
280 #define	ZSWR10_PRESET_ONES	0x80	/* preset CRC to all 1 (else all 0) */
281 
282 #define	ZSWR10_NRZ		0x00	/* NRZ encoding */
283 #define	ZSWR10_NRZI		0x20	/* NRZI encoding */
284 #define	ZSWR10_FM1		0x40	/* FM1 encoding */
285 #define	ZSWR10_FM0		0x60	/* FM0 encoding */
286 
287 #define	ZSWR10_GA_ON_POLL	0x10	/* go active on poll (loop mode) */
288 #define	ZSWR10_MARK_IDLE	0x08	/* all 1s (vs flag) when idle (SDLC) */
289 #define	ZSWR10_ABORT_ON_UNDERRUN 0x4	/* abort on xmit underrun (SDLC) */
290 #define	ZSWR10_LOOP_MODE	0x02	/* loop mode (SDLC) */
291 #define	ZSWR10_6_BIT_SYNC	0x01	/* 6 bits per sync char (sync modes) */
292 
293 /*
294  * Bits in Write Register 11 (`Clock Mode Control').  Bits 6&5, 4&3, and
295  * 1&0 are taken as units.  Various bits depend on other bits in complex
296  * ways; see the Zilog manual.
297  */
298 #define	ZSWR11_XTAL		0x80	/* have xtal between RTxC* and SYNC* */
299 					/* (else have TTL oscil. on RTxC*) */
300 #define	ZSWR11_RXCLK_RTXC	0x00	/* recv clock taken from RTxC* pin */
301 #define	ZSWR11_RXCLK_TRXC	0x20	/* recv clock taken from TRxC* pin */
302 #define	ZSWR11_RXCLK_BAUD	0x40	/* recv clock taken from BRG */
303 #define	ZSWR11_RXCLK_DPLL	0x60	/* recv clock taken from DPLL */
304 
305 #define	ZSWR11_TXCLK_RTXC	0x00	/* xmit clock taken from RTxC* pin */
306 #define	ZSWR11_TXCLK_TRXC	0x08	/* xmit clock taken from TRxC* pin */
307 #define	ZSWR11_TXCLK_BAUD	0x10	/* xmit clock taken from BRG */
308 #define	ZSWR11_TXCLK_DPLL	0x18	/* xmit clock taken from DPLL */
309 
310 #define	ZSWR11_TRXC_OUT_ENA	0x04	/* TRxC* pin will be an output */
311 					/* (unless it is being used above) */
312 #define	ZSWR11_TRXC_XTAL	0x00	/* TRxC output from xtal oscillator */
313 #define	ZSWR11_TRXC_XMIT	0x01	/* TRxC output from xmit clock */
314 #define	ZSWR11_TRXC_BAUD	0x02	/* TRxC output from BRG */
315 #define	ZSWR11_TRXC_DPLL	0x03	/* TRxC output from DPLL */
316 
317 /*
318  * Formula for Write Registers 12 and 13 (`Lower Byte of Baud Rate
319  * Generator Time Constant' and `Upper Byte of ...').  Inputs:
320  *
321  *	f	BRG input clock frequency (in Hz) AFTER division
322  *		by 1, 16, 32, or 64 (per clock divisor in WR4)
323  *	bps	desired rate in bits per second (9600, etc)
324  *
325  * We want
326  *
327  *	  f
328  *	----- + 0.5 - 2
329  *	2 bps
330  *
331  * rounded down to an integer.  This can be computed entirely
332  * in integer arithmetic as:
333  *
334  *	f + bps
335  *	------- - 2
336  *	 2 bps
337  */
338 #define	BPS_TO_TCONST(f, bps)	((((f) + (bps)) / (2 * (bps))) - 2)
339 
340 /* inverse of above: given a BRG Time Constant, return Bits Per Second */
341 #define	TCONST_TO_BPS(f, tc)	((f) / 2 / ((tc) + 2))
342 
343 /*
344  * Bits in Write Register 14 (`Miscellaneous Control Bits').
345  * Bits 7 through 5 are taken as a unit and make up a `DPLL command'.
346  */
347 #define	ZSWR14_DPLL_NOOP	0x00	/* leave DPLL alone */
348 #define	ZSWR14_DPLL_SEARCH	0x20	/* enter search mode */
349 #define	ZSWR14_DPLL_RESET_CM	0x40	/* reset `clock missing' in RR10 */
350 #define	ZSWR14_DPLL_DISABLE	0x60	/* disable DPLL (continuous search) */
351 #define	ZSWR14_DPLL_SRC_BAUD	0x80	/* set DPLL src = BRG */
352 #define	ZSWR14_DPLL_SRC_RTXC	0xa0	/* set DPLL src = RTxC* or xtal osc */
353 #define	ZSWR14_DPLL_FM		0xc0	/* operate in FM mode */
354 #define	ZSWR14_DPLL_NRZI	0xe0	/* operate in NRZI mode */
355 
356 #define	ZSWR14_LOCAL_LOOPBACK	0x10	/* set local loopback mode */
357 #define	ZSWR14_AUTO_ECHO	0x08	/* set auto echo mode */
358 #define	ZSWR14_DTR_REQ		0x04	/* DTR* / REQ* pin gives REQ* */
359 #define	ZSWR14_BAUD_FROM_PCLK	0x02	/* BRG clock taken from PCLK */
360 					/* (else from RTxC* pin or xtal osc) */
361 #define	ZSWR14_BAUD_ENA		0x01	/* enable BRG countdown */
362 
363 /*
364  * Bits in Write Register 15 (`External/Status Interrupt Control').
365  * Most of these cause status interrupts whenever the corresponding
366  * bit or pin changes state (i.e., any rising or falling edge).
367  *
368  * NOTE: ZSWR15_SDLC_FIFO & ZSWR15_ENABLE_ENHANCED should not be
369  * set on an NMOS 8530. Also, ZSWR15_ENABLE_ENHANCED is only
370  * available on the 85230.
371  */
372 #define	ZSWR15_BREAK_IE		0x80	/* enable break/abort status int */
373 #define	ZSWR15_TXUEOM_IE	0x40	/* enable TX underrun/EOM status int */
374 #define	ZSWR15_CTS_IE		0x20	/* enable CTS* pin status int */
375 #define	ZSWR15_SYNCHUNT_IE	0x10	/* enable SYNC* pin/hunt status int */
376 #define	ZSWR15_DCD_IE		0x08	/* enable DCD* pin status int */
377 #define	ZSWR15_SDLC_FIFO	0x04	/* enable SDLC FIFO enhancements */
378 #define	ZSWR15_ZERO_COUNT_IE	0x02	/* enable BRG-counter = 0 status int */
379 #define	ZSWR15_ENABLE_ENHANCED	0x01	/* enable writing WR7' at reg 7 */
380 
381 /*
382  * Bits in Read Register 0 (`Transmit/Receive Buffer Status and External
383  * Status').
384  */
385 #define	ZSRR0_BREAK		0x80	/* break/abort detected */
386 #define	ZSRR0_TXUNDER		0x40	/* transmit underrun/EOM (sync) */
387 #define	ZSRR0_CTS		0x20	/* clear to send */
388 #define	ZSRR0_SYNC_HUNT		0x10	/* sync/hunt (sync mode) */
389 #define	ZSRR0_DCD		0x08	/* data carrier detect */
390 #define	ZSRR0_TX_READY		0x04	/* transmit buffer empty */
391 #define	ZSRR0_ZERO_COUNT	0x02	/* zero count in baud clock */
392 #define	ZSRR0_RX_READY		0x01	/* received character ready */
393 
394 /*
395  * Bits in Read Register 1 (the Zilog book does not name this one).
396  */
397 #define	ZSRR1_EOF		0x80	/* end of frame (SDLC mode) */
398 #define	ZSRR1_FE		0x40	/* CRC/framing error */
399 #define	ZSRR1_DO		0x20	/* data (receiver) overrun */
400 #define	ZSRR1_PE		0x10	/* parity error */
401 #define	ZSRR1_RC0		0x08	/* residue code 0 (SDLC mode) */
402 #define	ZSRR1_RC1		0x04	/* residue code 1 (SDLC mode) */
403 #define	ZSRR1_RC2		0x02	/* residue code 2 (SDLC mode) */
404 #define	ZSRR1_ALL_SENT		0x01	/* all chars out of xmitter (async) */
405 
406 /*
407  * Read Register 2 in B channel contains status bits if VECTOR_INCL_STAT
408  * is set.
409  */
410 
411 /*
412  * Bits in Read Register 3 (`Interrupt Pending').  Only channel A
413  * has an RR3.
414  */
415 			/*	0x80	   unused, returned as 0 */
416 			/*	0x40	   unused, returned as 0 */
417 #define	ZSRR3_IP_A_RX		0x20	/* channel A recv int pending */
418 #define	ZSRR3_IP_A_TX		0x10	/* channel A xmit int pending */
419 #define	ZSRR3_IP_A_STAT		0x08	/* channel A status int pending */
420 #define	ZSRR3_IP_B_RX		0x04	/* channel B recv int pending */
421 #define	ZSRR3_IP_B_TX		0x02	/* channel B xmit int pending */
422 #define	ZSRR3_IP_B_STAT		0x01	/* channel B status int pending */
423 
424 /*
425  * Bits in Read Register 10 (`contains some miscellaneous status bits').
426  */
427 #define	ZSRR10_1_CLOCK_MISSING	0x80	/* 1 clock edge missing (FM mode) */
428 #define	ZSRR10_2_CLOCKS_MISSING	0x40	/* 2 clock edges missing (FM mode) */
429 			/*	0x20	   unused */
430 #define	ZSRR10_LOOP_SENDING	0x10	/* xmitter controls loop (SDLC loop) */
431 			/*	0x08	   unused */
432 			/*	0x04	   unused */
433 #define	ZSRR10_ON_LOOP		0x02	/* SCC is on loop (SDLC/X.21 modes) */
434 
435 /*
436  * Bits in Read Register 15.  This register is one of the few that
437  * simply reads back the corresponding Write Register.
438  */
439 #define	ZSRR15_BREAK_IE		0x80	/* break/abort status int enable */
440 #define	ZSRR15_TXUEOM_IE	0x40	/* TX underrun/EOM status int enable */
441 #define	ZSRR15_CTS_IE		0x20	/* CTS* pin status int enable */
442 #define	ZSRR15_SYNCHUNT_IE	0x10	/* SYNC* pin/hunt status int enable */
443 #define	ZSRR15_DCD_IE		0x08	/* DCD* pin status int enable */
444 			/*	0x04	   unused, returned as zero */
445 #define	ZSRR15_ZERO_COUNT_IE	0x02	/* BRG-counter = 0 status int enable */
446 			/*	0x01	   unused, returned as zero */
447