master
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright 2004 by Peter Grehan. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef _VIA6522REG_H_
31#define _VIA6522REG_H_
32
33/* Registers */
34#define REG_OIRB 0 /* Input/output register B */
35#define REG_OIRA 1 /* Input/output register A */
36#define REG_DDRB 2 /* Data direction register B */
37#define REG_DDRA 3 /* Data direction register A */
38#define REG_T1CL 4 /* T1 low-order latch/low-order counter */
39#define REG_T1CH 5 /* T1 high-order counter */
40#define REG_T1LL 6 /* T1 low-order latches */
41#define REG_T1LH 7 /* T1 high-order latches */
42#define REG_T2CL 8 /* T2 low-order latch/low-order counter */
43#define REG_T2CH 9 /* T2 high-order counter */
44#define REG_SR 10 /* Shift register */
45#define REG_ACR 11 /* Auxiliary control register */
46#define REG_PCR 12 /* Peripheral control register */
47#define REG_IFR 13 /* Interrupt flag register */
48#define REG_IER 14 /* Interrupt-enable register */
49#define REG_OIRA_NH 15 /* Input/output register A: no handshake */
50
51
52/* Auxiliary control register (11) */
53#define ACR_SR_NONE 0x0 /* Disabled */
54#define ACR_SR_DIR 0x4 /* Bit for shift-register direction 1=out */
55#define ACR_SRI_T2 0x1 /* Shift in under control of T2 */
56#define ACR_SRI_PHI2 0x2 /* " " " " " PHI2 */
57#define ACR_SRI_EXTCLK 0x3 /* " " " " " external clk */
58#define ACR_SRO 0x4 /* Shift out free running at T2 rate */
59#define ACR_SRO_T2 0x5 /* Shift out under control of T2 */
60#define ACR_SRO_PHI2 0x6 /* " " " " " PHI2 */
61#define ACR_SRO_EXTCLK 0x7 /* " " " " " external clk */
62
63#define ACR_T1_SHIFT 5 /* bits 7-5 */
64#define ACR_SR_SHIFT 2 /* bits 4-2 */
65
66
67/* Peripheral control register (12) */
68#define PCR_INTCNTL 0x01 /* interrupt active edge: +ve=1, -ve=0 */
69
70#define PCR_CNTL_MASK 0x3 /* 3 bits */
71#define PCR_CNTL_NEDGE 0x0 /* Input - negative active edge */
72#define PCR_CNTL_INEDGE 0x1 /* Interrupt - negative active edge */
73#define PCR_CNTL_PEDGE 0x2 /* Input - positive active edge */
74#define PCR_CNTL_IPEDGE 0x3 /* Interrupt - positive active edge */
75#define PCR_CNTL_HSHAKE 0x4 /* Handshake output */
76#define PCR_CNTL_PULSE 0x5 /* Pulse output */
77#define PCR_CNTL_LOW 0x6 /* Low output */
78#define PCR_CNTL_HIGH 0x7 /* High output */
79
80#define PCR_CB2_SHIFT 5 /* bits 7-5 */
81#define PCR_CB1_SHIFT 4 /* bit 4 */
82#define PCR_CA2_SHIFT 1 /* bits 3-1 */
83#define PCR_CA1_SHIFT 0 /* bit 0 */
84
85/* Interrupt flag register (13) */
86#define IFR_CA2 0x01
87#define IFR_CA1 0x02
88#define IFR_SR 0x04
89#define IFR_CB2 0x08
90#define IFR_CB1 0x10
91#define IFR_T2 0x20
92#define IFR_T1 0x40
93#define IFR_IRQB 0x80 /* status of IRQB output pin */
94
95/* Interrupt enable register (14) */
96#define IER_CA2 IFR_CA2
97#define IER_CA1 IFR_CA1
98#define IER_SR IFR_SR
99#define IER_CB2 IFR_CB2
100#define IER_CB1 IFR_CB1
101#define IER_T2 IFR_T2
102#define IER_T1 IFR_T1
103#define IER_IRQB IFR_IRQB
104
105#endif /* _VIA6522REG_H_ */