| #ifndef _MC6821_H_ | |
| #define _MC6821_H_ | |
| /* | |
| * This file describes the memery mapping of the MC6821 PIA. | |
| * The unions describe overlayed registers. Which of them is used is | |
| * determined by bit 2 of the corresponding control register. | |
| * this files expects the PIA_REG_PADWIDTH to be defined the numeric | |
| * value of the register spacing. | |
| * | |
| * Data came from MFC-31-Developer Kit (from Ralph Seidel, | |
| * zodiac@darkness.gun.de) and Motorola Data Sheet (from | |
| * Richard Hirst, srh@gpt.co.uk) | |
| * | |
| * 6.11.95 copyright Joerg Dorchain (dorchain@mpi-sb.mpg.de) | |
| * | |
| */ | |
| #ifndef PIA_REG_PADWIDTH | |
| #define PIA_REG_PADWIDTH 255 | |
| #endif | |
| struct pia { | |
| union { | |
| volatile u_char pra; | |
| volatile u_char ddra; | |
| } ua; | |
| u_char pad1[PIA_REG_PADWIDTH]; | |
| volatile u_char cra; | |
| u_char pad2[PIA_REG_PADWIDTH]; | |
| union { | |
| volatile u_char prb; | |
| volatile u_char ddrb; | |
| } ub; | |
| u_char pad3[PIA_REG_PADWIDTH]; | |
| volatile u_char crb; | |
| u_char pad4[PIA_REG_PADWIDTH]; | |
| }; | |
| #define ppra ua.pra | |
| #define pddra ua.ddra | |
| #define pprb ub.prb | |
| #define pddrb ub.ddrb | |
| #define PIA_C1_ENABLE_IRQ (1<<0) | |
| #define PIA_C1_LOW_TO_HIGH (1<<1) | |
| #define PIA_DDR (1<<2) | |
| #define PIA_IRQ2 (1<<6) | |
| #define PIA_IRQ1 (1<<7) | |
| #endif |