Users Manual

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 1455 of 1852
Nov 30, 2020
RX23W Group 40. SD Host Interface (SDHIa)
40.3 SDHI Operation
40.3.1 Data Block Format of the SD Card
The SDHI has a default bus mode (1-bit width) that uses just the SDHI_D0 pin as a data line and a wide bus mode (4-bit
width) that uses pins SDHI_D0 to SDHI_D3.
Figure 40.2 shows the transfer format when the SDOPT.WIDTH bit is 1
(default bus mode), and
Figure 40.3 shows the transfer format when the SDOPT.WIDTH bit is 0 (wide bus mode).
Figure 40.2 Transfer Format in Default Bus Mode
Figure 40.3 Transfer Format in Wide Bus Mode
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E
Start Byte 0
7 0 15 8
Byte 1
23 16
Byte 2
31 24
Byte 3
Stop
SDHI_D0
Start Byte 0 Byte 1 Byte 2 Byte 3 Stop
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E7 3 15 11 23 19 31 27SDHI_D3
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E6 2 14 10 22 18 30 26
SDHI_D2
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E5 1 13 9 21 17 29 25
SDHI_D1
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E4 0 12 8 20 16 28 24
SDHI_D0