
4/29/2020
Godson 3A2000 / 3B2000 Processor User Manual
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Godson 3A2000 / 3B2000 Processor User Manual Part 1
11 Low-speed IO controller configuration
Loongson No. 3 I / O controller includes PCI controller, LPC controller, UART controller, SPI controller, GPIO
And configuration registers. These I / O controllers share an AXI port, and the CPU request is sent to the phase after address decoding
Should be the equipment.
11.1 PCI controller
The PCI controller of Loongson 3 can be used as the main bridge to control the entire system, or it can work as a common PC device.
On the PCI bus. Its implementation conforms to the PCI 2.3 specification. The PCI controller of Godson 3 also has a built-in PCI arbiter.
The configuration header of the PCI controller is located at 256 bytes starting at 0x1FE00000,
Table 11-1 PCI controller configuration header
Byte 3
Byte 2
Byte 1
Byte 0
address
Device ID
Vendor ID
00
Status
Command
04
Class Code
Revision ID
08
BIST
Header Type
Latency Timer
CacheLine Size
0C
Base Address Register 0
10
Base Address Register 1
14
Base Address Register 2
18
Base Address Register 3
1C
Base Address Register 4
20
Base Address Register 5
twenty four
28
Subsystem ID
Subsystem Vendor ID
2C
30
Capabilities Pointer
34
38
Maximum Latency
Minimum Grant
Interrupt Pin
Interrupt Line
3C
Implementation Specific Register (ISR40)
40
Implementation Specific Register (ISR44)
44
Implementation Specific Register (ISR48)
48
Implementation Specific Register (ISR4C)
4C
Implementation Specific Register (ISR50)
50
Implementation Specific Register (ISR54)
54
Implementation Specific Register (ISR58)
58
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Godson 3A2000 / 3B2000 Processor User Manual Part 1
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PCIX Command Register
E0
PCIX Status Register
E4
The PCIX controller of Loongson 3A2000 supports three 64-bit windows, composed of {BAR1, BAR0}, {BAR3, BAR2},
{BAR5, BAR4} Base address of three pairs of register configuration windows 0, 1, 2. The size, enable, and other details of the window
Three corresponding registers PCI_Hit0_Sel, PCI_Hit1_Sel, PCI_Hit2_Sel control, please refer to Table 2 for specific bit fields