blob: 8d8667cde26a329762879dcffd9ab690df756092 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
package com.zylin.zpu.simulator;
import com.zylin.zpu.simulator.exceptions.CPUException;
import com.zylin.zpu.simulator.exceptions.MemoryAccessException;
public class Abel extends Simulator
{
protected int getIO()
{
return 0x8000;
}
protected int ioRead(int addr) throws CPUException
{
switch (addr)
{
case 0xc000:
return syscall.readUART();
/* FIFO empty? bit 0, FIFO full bit 1(never the case) */
case 0xc004:
return syscall.readFIFO();
case 0x9000:
case 0x9004:
case 0x9008:
case 0x900c:
case 0x9010:
case 0x9014:
case 0x9018:
case 0x901c:
return readSampledTimer(addr, 0x9000);
case 0x8800:
return readMHz();
default:
throw new MemoryAccessException();
}
}
/*
; Read/write are on different addresses
; The registers are 8 bits and mapped to bit[7:0]
;
; 0xC000 Write: Writes to UART TX FIFO (4 byte FIFO)
; Read : Reads from UART RX FIFO (4 byte FIFO)
; 0xC004 Read : UART status register
; Bit 0 = RX FIFO empty
; Bit 1 = TX FIFO full
; 0xA000 Write: 8 LED's
*/
/*
0x9000 Write: bit 0: 1= reset counter
0= counter running
bit 1: 1= sample counter (when set to 1)
0=not used
Read : counter bit[7:0]
0x9004 Read: counter bit [15:8]
0x9008 Read: counter bit [23:16]
0x900C Read: counter bit [31:24]
0x9010 Read: counter bit [39:32]
0x9014 Read: counter bit [47:40]
0x9018 Read: counter bit [55:48]
0x901C Read: counter bit [63:56]
0x8800 Read: unsigned 8-bit integer with FPGA frequency (in MHz)
*/
protected void ioWrite(int addr, int val) throws MemoryAccessException
{
switch (addr)
{
case 0x9000:
writeTimerSampleReg(val);
case 0xc000:
syscall.writeUART(val);
break;
default:
throw new MemoryAccessException();
}
}
Abel() throws CPUException
{
}
protected boolean emulateConfig()
{
return true;
}
protected int getStartStack()
{
return getRAMSIZE()-8;
}
protected int getRAMSIZE()
{
return 32768;
}
}
|