R01UH0823EJ0100 Rev.1.00
Page 1447 of 1823
Jul 31, 2019
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.
shows the transfer format when the SDOPT.WIDTH bit is 1
(default bus mode), and
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)
E
7
3 15 11 23 19 31 27
SDHI_D3
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E
6
2 14 10 22 18 30 26
SDHI_D2
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E
5
1 13 9 21 17 29 25
SDHI_D1
S
CRC16
(15)
CRC16
(14)
CRC16
(1)
CRC16
(0)
E
4
0 12 8 20 16 28 24
SDHI_D0