
4/29/2020
Loongson 3A3000 / 3B3000 Processor User Manual
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High temperature down frequency control register
Thsens_freq_scale
0x3ff01480
RW
[8: 8]: Scale_en0: High temperature frequency reduction enable 0
[11:10]: Scale_Sel0: Select the temperature sensor input source of high temperature down-conversion 0
[14:12]: Scale_freq0: frequency division value when frequency is reduced
[23:16]: Scale_gate1: High temperature threshold 1, exceeding this temperature will reduce the frequency
[24:24]: Scale_en1: High temperature frequency reduction enable 1
[27:26]: Scale_Sel1: Select the temperature sensor input source for high temperature down-conversion 1
[30:28]: Scale_freq1: frequency division value when frequency is reduced
[39:32]: Scale_gate2: High temperature threshold value 2, if this temperature is exceeded, frequency will be reduced
[40:40]: Scale_en2: High temperature frequency reduction enable 2
[43:42]: Scale_Sel2: Select the temperature sensor input source for high temperature down-conversion 2
[46:44]: Scale_freq2: frequency division value when frequency is reduced
[55:48]: Scale_gate3: High temperature threshold 3, over this temperature will reduce the frequency
[56:56]: Scale_en3: High temperature frequency reduction enable 3
[59:58]: Scale_Sel3: Select the temperature sensor input source for high temperature down-conversion 3
[62:60]: Scale_freq3: Frequency division value when frequency is reduced
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Godson 3A3000 / 3B3000 Processor User Manual • Volume 1
9 DDR2 / 3 SDRAM controller configuration
The design of the integrated memory controller inside Loongson No. 3 processor complies with the industry standard of DDR2 / 3 SDRAM (JESD79-2
And JESD79-3). In the Godson 3 processor, all memory read / write operations are implemented in compliance with JESD79-2B and
The provisions of JESD79-3.
9.1 DDR2 / 3 SDRAM controller function overview
Loongson No. 3 processor supports a maximum of 4 CS (implemented by 4 DDR2 SDRAM chip select signals, that is, two double-sided memory
Article), contains a total of 19-bit address bus (ie: 16-bit row and column address bus and 3-bit logical Bank bus).
When Loongson No. 3 processor chooses to use different memory chip types, it can adjust the DDR2 / 3 controller parameter settings
To support. Among them, the maximum number of chip selects (CS_n) supported is 4, the number of row addresses (RAS_n) is 16, and the column addresses (CAS_n)
The number is 15, and the number of logical volume selection (BANK_n) is 3.
The physical address of the memory request sent by the CPU can be mapped to many different addresses according to different configurations inside the controller
Shoot.
The memory control circuit integrated in the Loongson 3 processor only accepts memory read / write requests from the processor or external devices
Demand, in all memory read / write operations, the memory control circuit is in the slave state.
The memory controller in Loongson No. 3 processor has the following characteristics:
●
Full pipeline operation of commands and read and write data on the interface