Intel PXA26X User Manual Page 251

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Intel® PXA26x Processor Family Developer’s Manual 6-61
Memory Controller
6.9.2 Expansion Memory Configuration Register (MECR)
To eliminate external hardware, two bits, shown in Table 6-31, are used to signal the memory
controller when a card (16-Bit PC Card/Compact Flash) is inserted in the socket and the number of
cards supported in the system. The number-of-sockets bit is required because the PSKTSEL pin is
used as the nOE for the data transceivers in single socket mode. Use the card-is-there bit to reduce
external hardware by ignoring nIOIS16 and nPWAIT when there is no card inserted in the socket.
6.9.3 16-Bit PC Card Overview
The PXA26x processor family 16-bit PC Card interface provides control for one 16-bit PC Card
card slot with a PSKTSEL pin for support of a second slot. The PXA26x processor family interface
supports 8- and 16-bit peripherals and handles common memory, I/O, and attribute-memory
accesses. The duration of each access is based on the values programmed in the fields in the
MCMEMx, MCATTx, and MCIOx registers. Figure 6-24 shows the memory map for the 16-bit PC
Card space.
Table 6-31. MECR Configuration Register Bitmap
4800 0014 MECR Processor
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Reserved
CIT
NOS
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bits Name Description
31:2 Reserved
1CIT
CARD-IS-THERE:
0 – No card inserted
1 – Card inserted
Must be set by software when at least one card is present and must be cleared when all
cards are removed.
0NOS
NUMBER-OF-SOCKETS:
0 – 1 Socket
1 – 2 Sockets
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