
VAR-320SBC Reference Guide
Copyright © 2008 Variscite
Signal
Pin number Type Description
GPIO
STD_TXD
P1-42
O
ST UART TXD
107
STD_RXD P1-44
I
ST UART RXD
108
4.4. SD/MMC Ports
The VAR-320SBC outputs 2 SD/MMC ports.
The MultiMediaCard (MMC) and Secure Digital (SD/SDIO) controller (MMC/SD/SDIO controller)
provide a software-accessible hardware link between the PXA320 and the MMC stack (a set of
memory cards). The MMC/SD/SDIO controller supports Multimedia Card, Secure Digital, and
Secure Digital I/O communication protocols. The PXA320 contains two independent
MMC/SD/SDIO controllers.
•
1-bit and 4-bit data transfers are supported for MMC, SD, and SDIO communication
protocols
•
Data transfer clock of 19.5 MHz
•
Support for all valid MMC and SD/SDIO protocol data-transfer modes
•
Interrupt-based application interface to control software interaction
•
Multiple MMC cards are supported when using the MMC communications protocol
•
Only one SD or SDIO card is supported when using the SD or SDIO communications
protocol per controller.
•
Up to two MMC or SD/SDIO cards are supported when using the SPI communications
protocol. Mixed card types are supported only by the SPI communications protocol per
controller.
Signal
Pin number Type Description
GPIO
MMC_CLK
P1-102
O
SD/MMC Bus clock
22
MMC_CMD_0 P1-104
O SD/MMC
Command
23
MMC_DAT_0 P1-112 I SD/MMC
Data
18
MMC_DAT_1 P1-114 I SD/MMC
Data
19
MMC_DAT_2 P1-116 O SD/MMC
Data
20
MMC_DAT_3 P1-118 O SD/MMC
Data
21
MMC2_CLK
P1-120
O
SD/MMC 2 Bus clock
28
MMC2_CMD
P1-124
O
SD/MMC 2 Command
29
MMC2_DAT_0
P1-126
I
SD/MMC 2 Data
24
MMC2_DAT_1
P1-128
I
SD/MMC 2 Data
25
MMC2_DAT_2
P1-130
O
SD/MMC 2 Data
26
MMC2_DAT_3
P1-132
O
SD/MMC 2 Data
27
4.5. LCD Interface
17