| #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 |