Information

Enhanced Secure Digital Host Controller
MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1
Freescale Semiconductor 11-5
Table 11-1 shows the properties of the eSDHC I/O signals.
11.4 Memory Map/Register Definition
Table 11-2 shows the memory mapped registers of the eSDHC module and their offsets. It lists the offset,
name, and a cross-reference to the complete description of each register. Note that the full register address
is comprised of IMMRBAR together with the eSDHC block base address and offset listed in Table 11-2.
Undefined 4-byte address spaces within offset 0x000–0xFFF are reserved.
NOTE
All eSDHC registers must be accessed as aligned 4-byte quantities.
Accesses to the eSDHC registers that are less than 4-bytes are not supported.
Table 11-1. Signal Properties
Name Port Function Reset State Pull up/Pull down Required
SD_CLK O Clock for MMC/SD/SDIO card 0 N/A
SD_CMD I/O Command line to card High
impedance
Pull up
SD_DAT3 I/O 4-bit mode: DAT3 line or configured as card
detection pin
1-bit mode: May be configured as card detection pin
High
impedance
Board should have 100-K
pull down. The card drives
50-K pull up as required by
the SD Card Specification.
SD_DAT2 I/O 4-bit mode: DAT2 line or read wait
1-bit mode: Read wait
High
impedance
Pull up
SD_DAT1 I/O 4-bit mode: DAT1 line or interrupt detect
1-bit mode: Interrupt detect
High
impedance
Pull up
SD_DAT0 I/O DAT0 line or busy-state detect High
impedance
Pull up
SD
_CD I Card detection pin
•SD_CD
= HIGH implies card is not present
•SD_CD= LOW implies card is present.
N/A Board should have 100-K
pull up on the SD_CD signal
and a 330  pull down on the
common pin of the Write
Protect/Card Detect switch
on the SD card connector.
SD_WP I Card write protect detect; if not used, tied low
• SD_WP = HIGH implies the write protect switch is
enabled on the card (Writes disabled)
• SD_WP = LOW implies write protect switch is
disabled on the card (Writes enabled)
N/A Board should have 100-K
pull up on the SD_WP signal
and a 330  pull down on the
common pin of the Write
Protect/Card Detect switch
on the SD card connector.