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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef _MC6821_H_ |
| 2 | #define _MC6821_H_ |
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| 3 | |||
| 4 | /* |
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| 5 | * This file describes the memery mapping of the MC6821 PIA. |
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| 6 | * The unions describe overlayed registers. Which of them is used is |
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| 7 | * determined by bit 2 of the corresponding control register. |
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| 8 | * this files expects the PIA_REG_PADWIDTH to be defined the numeric |
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| 9 | * value of the register spacing. |
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| 10 | * |
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| 11 | * Data came from MFC-31-Developer Kit (from Ralph Seidel, |
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| 12 | * zodiac@darkness.gun.de) and Motorola Data Sheet (from |
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| 13 | * Richard Hirst, srh@gpt.co.uk) |
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| 14 | * |
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| 15 | * 6.11.95 copyright Joerg Dorchain (dorchain@mpi-sb.mpg.de) |
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| 16 | * |
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| 17 | */ |
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| 18 | |||
| 19 | #ifndef PIA_REG_PADWIDTH |
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| 20 | #define PIA_REG_PADWIDTH 255 |
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| 21 | #endif |
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| 22 | |||
| 23 | struct pia { |
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| 24 | union { |
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| 25 | volatile u_char pra; |
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| 26 | volatile u_char ddra; |
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| 27 | } ua; |
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| 28 | u_char pad1[PIA_REG_PADWIDTH]; |
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| 29 | volatile u_char cra; |
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| 30 | u_char pad2[PIA_REG_PADWIDTH]; |
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| 31 | union { |
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| 32 | volatile u_char prb; |
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| 33 | volatile u_char ddrb; |
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| 34 | } ub; |
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| 35 | u_char pad3[PIA_REG_PADWIDTH]; |
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| 36 | volatile u_char crb; |
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| 37 | u_char pad4[PIA_REG_PADWIDTH]; |
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| 38 | }; |
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| 39 | |||
| 40 | #define ppra ua.pra |
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| 41 | #define pddra ua.ddra |
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| 42 | #define pprb ub.prb |
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| 43 | #define pddrb ub.ddrb |
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| 44 | |||
| 45 | #define PIA_C1_ENABLE_IRQ (1<<0) |
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| 46 | #define PIA_C1_LOW_TO_HIGH (1<<1) |
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| 47 | #define PIA_DDR (1<<2) |
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| 48 | #define PIA_IRQ2 (1<<6) |
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| 49 | #define PIA_IRQ1 (1<<7) |
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| 50 | |||
| 51 | #endif |