Renesas R5S72621 User Manual
Section 16 Renesas Serial Peripheral Interface
R01UH0134EJ0400 Rev. 4.00
Page 847 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
16.4.10
Loopback Mode
When 1 is written to the SPLP bit in the pin control register (SPPCR), this module shuts off the
path between the MISO pin and the shift register, and between the MOSI pin and the shift register,
and connects the input path and the output path (reversed) of the shift register. This is called
loopback mode. When a serial transfer is executed in loopback mode, the transmit data becomes
the received data. Figure 16.24 shows the configuration of the shift register input/output paths for
the case where this module in master mode is set in loopback mode.
path between the MISO pin and the shift register, and between the MOSI pin and the shift register,
and connects the input path and the output path (reversed) of the shift register. This is called
loopback mode. When a serial transfer is executed in loopback mode, the transmit data becomes
the received data. Figure 16.24 shows the configuration of the shift register input/output paths for
the case where this module in master mode is set in loopback mode.
MOSI
MISO
Shift Register
Selector
Normal
Normal
Master
Loopback
Loopback
Slave
Normal
Master
Loopback
Slave
Figure 16.24 Configuration of Shift Register Input/Output Paths in Loopback Mode
(Master Mode)