LPC4370FET100において、外部シリアルパラレル変換(DS92LV2422)からの24bit幅データに対してDMAによる連続リードをする際に、21Mサンプル/秒でリードしようとしましたが、その半分の速度(10.5Mサンプル/秒)でしかCS信号が出力されませんでした。マイコン動作クロックは192MHzで動作させています。LPC4370FET100で、21Mサンプル/sでDMAによる連続リードする方法はないのでしょうか?また、LPC4370FET256でも同様でしょうか?
Hi
First of all, sorry for the later reply.
I had done a DMA performance test based on MCB4300 board with LPC4357 chip mounted, which with the same performance of LPC4370 DMA module.
The test using DMA channel 0 with source/destination transfer width word(32-bit) and source/destination burst size is 32.
Please check below test result:
Data transfer results [MODE: DMA]
=========================================
SOURCE ADDR: 0x28100000
DESTN ADDR: 0x28500000
XFER SIZE: 2097152 (Bytes)
CPU SPEED: 204.0 (MHz)
START TIME: 547956208 (ticks)
END TIME: 553271417 (ticks)
TIME TAKEN: 26054 (uSec(s))
SRC/DST COMP: MATCHING
It will use 26054us to transfer 2097152 bytes from SDRAM memory 0x28100000 to SDRAM memory 0x28500000.
As a calculated result, LPC4357 DMA module will transfer 80.49M bytes per seconde.
From customer description, the LPC4370 will read the 24-bit data from external serial parallel conversion (DS92LV 2422), which module as LPC4370 and DS92LV2422 interface?
If customer is using External Memory Controller(EMC) as interface?
The LPC4370 DAM performance should match with customer requirement.
Then, it need to check the interface module speed.
If customer using the EMC as interface, if it is possible to provide the related connection schematics and related initialization code.
Thank you for the attention.
Wish it helps.
Have a great day,
Ma Hui
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Hi
can you please put your question in English.
Thanks