4/29/2020
Godson 3A1000 Processor User Manual
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Loongson 3A1000 is the first product in Loongson No. 3 multi-core processor series. It is a single-node 4-core configuration.
The processor is manufactured with 65nm process and the highest working frequency is 1GHz. The main technical characteristics are as follows:
•
Four 64-bit super-scalar GS464 high-performance processor cores are integrated on-chip;
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On-chip integrated 4 MB split shared secondary cache (composed of 4 individual modules, each with a capacity of 1MB);
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Maintain the cache consistency of multi-core and I / O DMA access through the directory protocol;
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Godson 3A1000 Processor User Manual Part 1
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Two 64-bit 400MHz DDR2 / 3 controllers are integrated on-chip;
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Two 16-bit 800MHz HyperTransport controllers are integrated on-chip;
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Each 16-bit HT port is split into two 8-way HT ports for use.
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On-chip integrated 32-bit 100MHz PCIX / 66MHz PCI;
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Integrate 1 LPC, 2 UART, 1 SPI, 16 GPIO interfaces on-chip;
below.
# 0 L2
Cache
Level-1 Interconnection
Level-2 Interconnection
Memory
Controller
Low-end I / O
Controller
Enhance
d
HT1.0
Controlle
r
CORE
0
16B
16B
CORE
1
16B
16B
CORE
2
16B
16B
CORE
3
16B
16B
16B
16B
2B
2B
Enhance
d
HT1.0
Controlle
r
2B
2B
16B
16B
16B
16B
16B
16B
16B
16B
16B
# 1 L2
Cache
# 2 L2
Cache
# 3 L2
Cache
16B
16B
16B
16B
16B
16B
16B
16B
16B
16B
16B
16B
16B
16B
Memory
Controller
Config
Register
Test
Controlle
r
EJTAG
TAP
Controlle
r
Test Interface
JTAG
Interface
Inter-chip Link
SouthBridge
I / O Link
DDR2 / 3
SDRAM
Low-end I / O
Interface
Inter-chip Link
SouthBridge
I / O Link
16B
RDMA
Maxtrix
Transpositio
n
16B
16B
16B
NODE
Figure 1-3 Godson 3A1000 chip structure
The first level interconnection uses a 6x6 crossbar switch, which is used to connect four CPUs (as the main device) and four second level caches
Module (as a slave), and two IO ports (each port uses a Master and a Slave). First class
Each IO port connected to the interconnect switch is connected to a 16-bit HT controller, and each 16-bit HT port can also be used as
Two 8-bit HT ports are used. The HT controller is connected to the primary interconnection switch via a DMA controller. The DMA controller
Responsible for DMA DMA control and responsible for maintaining consistency between slices. The DMA controller of Godson 3 can also be realized through configuration
Prefetch and matrix transposition or relocation.
The second level interconnection uses a 5x4 crossbar switch, connecting 4 second level cache modules (as the main device), two DDR2
Memory controller, low-speed high-speed I / O (including PCI, LPC, SPI, etc.) and the control register module inside the chip.
The above two-level interconnect switches all use separate data channels for reading and writing. The width of the data channel is 128 bits.
The processor core has the same frequency to provide high-speed on-chip data transmission.
Based on Loongson No. 3 scalable interconnection architecture, 4 quad-core Loongson 3A1000 can be connected through HT port to form 4 chips
16-core SMP structure.
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