1 /*****************************************************************************/ 2 /* */ 3 /* _6522.h */ 4 /* */ 5 /* Internal include file, do not use directly */ 6 /* */ 7 /* */ 8 /* */ 9 /* (C) 2004 Stefan Haubenthal <polluks@sdf.lonestar.org> */ 10 /* */ 11 /* */ 12 /* This software is provided 'as-is', without any expressed or implied */ 13 /* warranty. In no event will the authors be held liable for any damages */ 14 /* arising from the use of this software. */ 15 /* */ 16 /* Permission is granted to anyone to use this software for any purpose, */ 17 /* including commercial applications, and to alter it and redistribute it */ 18 /* freely, subject to the following restrictions: */ 19 /* */ 20 /* 1. The origin of this software must not be misrepresented; you must not */ 21 /* claim that you wrote the original software. If you use this software */ 22 /* in a product, an acknowledgment in the product documentation would be */ 23 /* appreciated but is not required. */ 24 /* 2. Altered source versions must be plainly marked as such, and must not */ 25 /* be misrepresented as being the original software. */ 26 /* 3. This notice may not be removed or altered from any source */ 27 /* distribution. */ 28 /* */ 29 /*****************************************************************************/ 30 31 32 33 #ifndef __VIA_H 34 #define __VIA_H 35 36 37 38 /* Define a structure with the 6522 register offsets. 39 ** NOTE: The timer registers are not declared as 16 bit registers, because 40 ** the order in which the two 8 bit halves are written is important, and 41 ** the compiler doesn't guarantee any order when writing 16 bit values. 42 */ 43 struct __6522 { 44 unsigned char prb; /* Port register B */ 45 unsigned char pra; /* Port register A */ 46 unsigned char ddrb; /* Data direction register B */ 47 unsigned char ddra; /* Data direction register A */ 48 unsigned char t1_lo; /* Timer 1, low byte */ 49 unsigned char t1_hi; /* Timer 1, high byte */ 50 unsigned char t1l_lo; /* Timer 1 latch, low byte */ 51 unsigned char t1l_hi; /* Timer 1 latch, high byte */ 52 unsigned char t2_lo; /* Timer 2, low byte */ 53 unsigned char t2_hi; /* Timer 2, high byte */ 54 unsigned char sr; /* Shift register */ 55 unsigned char acr; /* Auxiliary control register */ 56 unsigned char pcr; /* Peripheral control register */ 57 unsigned char ifr; /* Interrupt flag register */ 58 unsigned char ier; /* Interrupt enable register */ 59 unsigned char pra2; /* Port register A w/o handshake */ 60 }; 61 62 63 64 /* End of _6522.h */ 65 #endif 66 67 68 69