4/29/2020
Godson 3A1000 Processor User Manual
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3
Configuration register
As shown in the table below. MMAP [4] means to allow instruction fetch, MMAP [5] means to allow block read, MMAP [7] means to use window
can.
Table 2-7 The space access attributes corresponding to the MMAP field
[4]
[5]
[7]
Allow fetching
Block read
Window enable
Compared with the address configuration of the first-level XBAR, the address configuration of the second-level XBAR adds the function of address translation. In contrast
Next, the window configuration of the first-level XBAR cannot perform address translation for Cache consistency requests, otherwise it is in the second-level cache
Will be inconsistent with the address of the first-level cache of the processor, resulting in incorrect maintenance of Cache consistency.
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Godson 3A1000 Processor User Manual Part 1
Window hit formula: (IN_ADDR & MASK) == BASE
New address conversion formula: OUT_ADDR = (IN_ADDR & ~ MASK) | {MMAP [63:10], 10'h0}
The address window conversion register is as follows.
Table 2-8 Secondary XBAR address window conversion register table
address
register
description
Default value
3ff0 0000 CPU_WIN0_BASE CPU window 0 base address 0x0
3ff0 0008 CPU_WIN1_BASE CPU window 1 base address 0x1000_0000
3ff0 0010 CPU_WIN2_BASE CPU window 2 base address 0x0
3ff0 0018 CPU_WIN3_BASE CPU window 3 base address 0x0
3ff0 0020 CPU_WIN4_BASE CPU window 4 base address 0x0
3ff0 0028 CPU_WIN5_BASE CPU window 5 base address 0x0
3ff0 0030 CPU_WIN6_BASE CPU window 6 base address 0x0
3ff0 0038 CPU_WIN7_BASE CPU window 7 base address 0x0
3ff0 0040 CPU_WIN0_MASK CPU window 0 mask
0xffff_ffff_f000_0000
3ff0 0048 CPU_WIN1_MASK CPU window 1 mask
0xffff_ffff_f000_0000
3ff0 0050 CPU_WIN2_MASK CPU window 2 mask
0x0
3ff0 0058 CPU_WIN3_MASK CPU window 3 mask
0x0
3ff0 0060 CPU_WIN4_MASK CPU window 4 mask
0x0
3ff0 0068 CPU_WIN5_MASK Mask of CPU window 5
0x0
3ff0 0070 CPU_WIN6_MASK CPU window 6 mask
0x0
3ff0 0078 CPU_WIN7_MASK CPU window 7 mask
0x0
3ff0 0080 CPU_WIN0_MMAP CPU window 0 new base address 0xf0
3ff0 0088 CPU_WIN1_MMAP CPU window 1 new base address 0x1000_00f2
3ff0 0090 CPU_WIN2_MMAP CPU window 2 new base address 0
3ff0 0098 CPU_WIN3_MMAP CPU window 3 new base address 0
3ff0 00a0 CPU_WIN4_MMAP CPU window 4 new base address 0x0
3ff0 00a8 CPU_WIN5_MMAP CPU window 5 new base address 0x0
3ff0 00b0 CPU_WIN6_MMAP CPU window 6 new base address 0
3ff0 00b8 CPU_WIN7_MMAP CPU window 7 new base address 0
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