Artesyn COMX-P40x0 ENP2 Installation and Use (January 2015) - Manual (Page 81)

Functional Description
COMX-P40x0 ENP2 Installation and Use (6806800R95C) 81
4.10 SDHC
The COMX-P40x0 ENP2 module provides an SD/MMC interface to the COM Express connector
to support expansion card options on the carrier board.
This module not only supports SD card but also Micro SD card in which there is no write-protect
signal. COM Express connector B57 is used to define whether an SD card or Micro SD card is
populated on the carrier board.
4.11 SPI Interface
The COMX-P40x0 ENP2 module provides a SPI bus from the P40x0 CPU with 4 chip select
signals. All SPI bus signals are routed to COM Express connectors.
4.12 LAN
The modules with gigabit Ethernet options route a port with LED control signals to the COM
Express connector. The supporting magnetics must be on the carrier board. RGMII is the
interface between the P40x0 MAC and external PHY. This interface is multiplexed with the
USB1 ULPI interface so modules with the gigabit Ethernet option should set RCW[EC1] to 00 to
select RGMII operation.
IO6 - GPO7 CD.B101
IO7 - GPO8 CD.B102
Table 4-6 GPIO
PCA955NAME - GPIO NAME COMX PLUG.PIN
Table 4-7 SD or Micro SD card on the Carrier
COM Express pin B57 Card on the carrier
1 SD card
0 (Default) Micro SD card