4/29/2020
Loongson 3A3000 / 3B3000 Processor User Manual
23
twenty four
3ff0 0138 PCI_WIN7_BASE PCI window 7 base address
0x0
3ff0 0140 PCI_WIN0_MASK PCI window 0 mask
0xffff_ffff_8000_0000
3ff0 0148 PCI_WIN1_MASK Mask of PCI window 1
0x0
3ff0 0150 PCI_WIN2_MASK PCI window 2 mask
0x0
3ff0 0158 PCI_WIN3_MASK PCI window 3 mask
0x0
3ff0 0160 PCI_WIN4_MASK PCI window 4 mask
0x0
3ff0 0168 PCI_WIN5_MASK PCI window 5 mask
0x0
3ff0 0170 PCI_WIN6_MASK Mask of PCI window 6
0x0
3ff0 0178 PCI_WIN7_MASK Mask of PCI window 7
0x0
3ff0 0180 PCI_WIN0_MMAP PCI window 0 new base address 0xf0
3ff0 0188 PCI_WIN1_MMAP PCI window 1 new base address 0x0
3ff0 0190 PCI_WIN2_MMAP New base address of PCI window 2 0
3ff0 0198 PCI_WIN3_MMAP PCI window 3 new base address 0
3ff0 01a0 PCI_WIN4_MMAP PCI window 4 new base address 0x0
3ff0 01a8 PCI_WIN5_MMAP PCI window 5 new base address 0x0
3ff0 01b0 PCI_WIN6_MMAP New base address of PCI window 6 0
3ff0 01b8 PCI_WIN7_MMAP PCI window 7 new base address 0
According to the default register configuration, after the chip is started, the address range of 0x00000000-0x0fffffff of the CPU
(256M) mapped to the address range of 0x00000000-0x0fffffff of DDR2, 0x10000000 of CPU-
0x1fffffff interval (256M) is mapped to PCI 0x10000000-0x1fffffff interval, PCIDMA 0x80000000
-The address range (256M) of 0x8fffffff is mapped to the address range of 0x00000000-0x0fffffff of DDR2.
The software can implement new address space routing and conversion by modifying the corresponding configuration registers.
In addition, when there is a read access to an illegal address due to CPU speculative execution, none of the eight address windows hit.
The configuration register module returns all 0 data to the CPU to prevent the CPU from dying.
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Godson 3A3000 / 3B3000 Processor User Manual • Volume 1
Table 2- 10 Level 2 XBAR default address configuration
Base address
High position
owner
0x0000_0000_0000_0000
0x0000_0000_0FFF_FFFF
No. 0 DDR controller
0x0000_0000_1000_0000
0x0000_0000_1FFF_FFFF
Low-speed I / O (PCI, etc.)
2.7 Chip configuration and sampling register
Chip configuration register (Chip_config) and chip sampling register in Godson 3A3000 / 3B3000
(Chip_sample) provides a mechanism to read and write the configuration of the chip.
Table 2-11 Chip Configuration Register (Physical Address 0x1fe00180)
Bit field
Field name
access
Reset value
description
3: 0-
RW
4'b7
Keep
4
MC0_disable_ddr2_confspace
RW
1'b0
Whether to disable MC0 DDR configuration space
5
-
RW
1'b0
Keep