NuMicro® NUC029LEE/NUC029SEE
32-bit Arm
®
Cortex
®
-M0 Microcontroller
Aug, 2018
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Rev 1.00
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UC02
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UC029
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SPI DMA Control Register (SPI_DMA)
Register
Offset
R/W
Description
Reset Value
SPI_DMA
0x38
R/W
SPI DMA Control Register
0x0000_0000
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
Reserved
7
6
5
4
3
2
1
0
Reserved
PDMA _RST RX_DMA_GO TX_DMA_GO
Bits
Description
[31:2]
Reserved
Reserved.
[2]
PDMA_RST
PDMA Reset
0 = No effect.
1 = Reset the PDMA control logic of the SPI controller. This bit will be cleared to 0
automatically.
[1]
RX_DMA_GO
Receive DMA Start
Setting this bit to 1 will start the receive PDMA process. The SPI controller will issue
request to PDMA controller automatically when the SPI receive buffer is not empty.
This bit will be cleared to 0 by hardware automatically after PDMA transfer is done.
If the software uses the receive PDMA function to access the received data of SPI
and does not use the transmit PDMA function, the GO_BUSY bit should be set by
software.
Enabling FIFO mode is recommended if the software uses more than one PDMA
channel to transfer data.
In Slave mode and when FIFO mode is disabled, if the software only uses one
PDMA channel for SPI receive PDMA function and the other PDMA channels are not
in use, the minimal suspend interval between two successive transactions must be
larger than (9 SPI slave peripheral clock p 4 APB clock periods) for Edge-
trigger mode or (9.5 SPI slave peripheral clock p 4 APB clock periods) for
Level-trigger mode.
[0]
TX_DMA_GO
Transmit DMA Start
Setting this bit to 1 will start the transmit PDMA process. SPI controller will issue
request to PDMA controller automatically. Hardware will clear this bit to 0
automatically after PDMA transfer done.
If the SPI transmit PDMA function is used to transfer data, the GO_BUSY bit should
not be set to 1 by software. The PDMA control logic of SPI controller will set it
automatically whenever necessary.
In Slave mode and when FIFO mode is disabled, the minimal suspend interval
between two successive transactions must be larger than (8 SPI clock p 14
APB clock periods) for edge-trigger mode or (9.5 SPI clock p 14 APB clock
periods) for level-trigger mode. If the 2-bit Transfer mode is enabled, additional 18
APB clock periods for the above conditions is required.