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GD32F403xx User Manual
457
19.3.
SPI function overview
19.3.1.
SPI block diagram
Figure 19-1. Block diagram of SPI
Clock Generator
MISO
NSS
SCK
MOSI
Tx/Rx Control Logic
TXBuffer
Shift Register
RX Buffer
Control
Registers
SYSCLK
LSB
MSB
PAD
O
I
APB
PAD
O
I
PAD
O
I
PAD
O
I
IO2
IO3
PAD
O
I
PAD
O
I
19.3.2.
SPI signal description
Normal configuration (Not Quad-SPI Mode)
Table 19-1. SPI signal description
Pin name
Direction
Description
SCK
I/O
Master: SPI clock output
Slave: SPI clock input
MISO
I/O
Master: data reception line
Slave: data transmission line
Master with bidirectional mode: not used
Slave with bidirectional mode: data transmission and
reception line.
MOSI
I/O
Master: data transmission line
Slave: data reception line
Master with bidirectional mode: data transmission and
reception line.
Slave with bidirectional mode: not used
NSS
I/O
Software NSS mode: not used
Master in hardware NSS mode: when NSSDRV=1, it is NSS
output, suitable for single master application; when
NSSDRV=0, it is NSS input, suitable for multi-master