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cc65/include/_6522.h
cuz 3d8aa8c7d8 Added a comment
git-svn-id: svn://svn.cc65.org/cc65/trunk@2976 b7a2c559-68d2-44c3-8de9-860c34a00d81
2004-04-08 17:43:28 +00:00

69 lines
3.4 KiB
C

/*****************************************************************************/
/* */
/* _6522.h */
/* */
/* Internal include file, do not use directly */
/* */
/* */
/* */
/* (C) 2004 Stefan Haubenthal <polluks@sdf.lonestar.org> */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#ifndef __VIA_H
#define __VIA_H
/* Define a structure with the 6522 register offsets.
* NOTE: The timer registers are not declared as 16 bit registers, because
* the order in which the two 8 bit halves are written is important, and
* the compiler doesn't guarantee any order when writing 16 bit values.
*/
struct __6522 {
unsigned char prb; /* Port register B */
unsigned char pra; /* Port register A */
unsigned char ddrb; /* Data direction register B */
unsigned char ddra; /* Data direction register A */
unsigned char t1_lo; /* Timer 1, low byte */
unsigned char t1_hi; /* Timer 1, high byte */
unsigned char t1l_lo; /* Timer 1 latch, low byte */
unsigned char t1l_hi; /* Timer 1 latch, high byte */
unsigned char t2_lo; /* Timer 2, low byte */
unsigned char t2_hi; /* Timer 2, high byte */
unsigned char sr; /* Shift register */
unsigned char acr; /* Auxiliary control register */
unsigned char pcr; /* Peripheral control register */
unsigned char ifr; /* Interrupt flag register */
unsigned char ier; /* Interrupt enable register */
unsigned char pra2; /* Port register A w/o handshake */
};
/* End of _6522.h */
#endif