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5. The function controlled by PCI_CONFIG [0] is changed to SPI startup enable. After setting to 1, it can be started from SPI FLASH. If make
Use the original 3A motherboard, it needs to be set to 0, start from LPC FLASH; if the motherboard already has SPI FLASH, you can
GPIO [0] as SPI_CS connection, and set PCI_CONFIG [0] to 1, start from SPI FLASH; (and 3A2000
Consistent)
6. The function controlled by PCI_CONFIG [7] is changed to forced HT1.0 mode. After setting it to 1, HT starts directly in 1.0 mode.
If you use a 3A780E motherboard, you currently need to set it to 1; if you use a 3A2H motherboard, no special settings are required; (and
3A2000 consistent)
7. For Godson 3A3000 / 3B3000A / B / C, CLKSEL [15:10] needs to be set to 6'b000000 or 6'b000001, and
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Reconfigure the frequency using software in PMON;
8. CLKSEL [9: 5] needs to be set to 5'b01111; use PMON to set the memory frequency. For Godson
3A3000 / 3B3000A / B / C, PMON must use NODE clock to divide frequency when frequency configuration;
3A2000 consistent)
9. CLKSEL [4: 0] needs to be set to 5'b01111; use PMON to set the processor core frequency. For Godson
3A3000 / 3B3000A / B / C, PMON must use L2 PLL as the main clock when configuring the frequency; (and 3A2000
Consistent)
10. For the 3A2H motherboard, you need to remove the pull-up resistors on HT0 / 1_powerok and HT0 / 1_resetn; (the original pull-up
The resistance of 300 ohms is not suitable for 3A and can also be removed) (same as 3A2000)
13.2 Frequency setting instructions
In order to be basically compatible with the frequency configuration of Godson 3A1000, the hardware frequency configuration range of Godson 3A3000 / 3B3000 is relatively
Narrow, in order to obtain a wider frequency range and better clock quality, it is mainly used in PMON in Godson 3A3000 / 3B3000
The software configuration method is the same as that of Godson 3B1500. Please refer to the PMON source code for the specific configuration method.
1. The frequency setting is completely set by the software, there is no need to modify CLKSEL when changing the frequency;
2. Stable working frequency of 1.25V core voltage: processor core frequency is set to 1400MHz, memory frequency is set to 700MHz,
HT controller is set to 800MHz, HT bus 800MHz / 1600MHz;
3. For Godson 3A3000 / 3B3000A / B / C, NODE CLOCK must use L2 PLL as the main clock, DDR CLOCK
The NODE clock must be used for frequency division;
13.3 PMON Change Guide
The following PMON changes are basically consistent with the 3A2000 / 3B2000 processor.