ARM Prospector P1100, User Manual, Page: 69 / 154

Hardware Description
ARM DUI 0122A Copyright © ARM Limited 2000. All rights reserved. 3-37
3.10 MMC interface
The MultiMedia Card (MMCs) is a standard data storage device, that use either flash or
ROM technology. It has a very small form factor of 32mm x 24mm and provides
storage capacities of up to 64MByte at the present time.
The P1100 uses the SPI bus to communicate with the MMCs. The maximum clock rate
for SPI accesses to the MMC is 1.8432MHz in the P1100 design.
The P1100 provides one or two sockets for MMCs:
• socket 1 is selected with
PLD_SPI_CS1
• socket 2, an optional stacked socket, is selected with
PLD_SPI_CS2
.
Figure 3-12 shows the architecture of the MMC interface.
Figure 3-12 MMC interface
Note
Socket 2 is not fitted as standard. It is possible to obtain a stacking socket to fit onto
socket 1. All pins except the chip select pin need to be soldered in parallel.
PLD_SPI_CS2
appears at a test point close to MMC socket, as shown in Figure 3-12.
The connector provides hot swap capability. The signal pins are recessed which allows
the power to connect and stabilize before logic signals are applied to the card. The cards
and connectors are keyed to prevent incorrect insertion. The +3V supply is permanently
enabled.
CPU_SPI_SCLK
CPU_SPI_RXD
CPU_SPI_TXD
CPU_SPI_CS[2:0]
PLD_SPI_nEN
PLD_SPI_nCS2
PLD_SPI_nCS1
SA-1100
System
controller
PLD
3-to-8
decoder
MMC
(socket 1)
MMC
(socket 2)
JP18
&