AN4300 datasheet(28/40 Pages) STMICROELECTRONICS

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MCU initialization

AN4300

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DocID024675 Rev 2

Figure 22. SPI_Vbat_SetTCD function

The function InitDMA_1 configures the eDMA channels to collect the diagnosis

automatically. For this reason the following channels are configured as described below:

• DMA CH0, CH7, CH8 and CH9 are configured to trigger the start counter of the

eMIOS0_CH1 when the SYNC_MUX comes from M06_1, M06_2, M06_3 and M06_4

respectively.

• DMA CH1 is configured to trigger the stop of counter of the eMIOS0_CH1

• DMA CH1 is linked to DMA CH2. In this way when the CH1 finishes it starts the DMA CH2

transmission which allows the start of the ADC conversion.

• DMA CH5 is configured to send, by SPI, the configuration to the MUX for the active M06

to select the right channel connected to the CS and with CS_SYNC.

• DMA CH4 is configured to transfer the value of the 4 Data Registers relative to the 4 ADC

channels linked to the 4 M06 to a buffer in the memory, This is done each trigger because

it is necessary to read all ADC channels that can trigger DMA transfers.

• DMA CH10 is configured to transfer the value converted by ADC to the final RAM

structure. The scatter gather feature is used to change the TDC to adapt the ADC Data

AN4300 Datasheet(PDF) 28 Page - STMicroelectronics