Pc Card Memory-Mode Enable Signals; Pc Card Memory Mapping; Table 12-3. Supported 8-Bit Accesses; Table 12-4. Supported 16-Bit Accesses - Cirrus Logic EP93 Series User Manual

Static Memory Controller
EP93xx User's Guide

12.4 PC Card Memory-Mode Enable Signals

PC Card memory-mode enable signals, nPC_CE1 and nPC_CE2, are output on pin MCELn
and pin MCEHn, respectively. Along with the address signal output on pin AD[0] and the data
signals input or output on pins DA[15:8] and DA[7:0], the nPC_CE1 and nPC_CE2 signals
specify the type of access that is being made to the particular segment of memory in the PC
Card, as shown in
12
Note: Prior to version 8.0 of the PCMCIA specification, two valid types of odd-byte accesses to a

12.5 PC Card Memory Mapping

The address mapping for access to an 8- or 16-bit PC Card is shown in
Table
Note: It is up to the programmer to provide an even address for all attribute memory access
Note: In
12-8
Table 12-3
Access
Stand by (no access)
Even Byte Access
Odd Byte Access
Access
Stand by (no access)
Even Byte Access
Odd Byte Access
Both Byte Access
16-bit PC Card were defined as shown in
odd-byte access to 16-bit PC Cards.
Access
Type 1 - Odd-Byte Access
Type 2 - Odd-Byte Access
12-7, respectively.
operations (see PCMCIA Spec. 2.1), because the PCMCIA controller will generate the
physical address as shown in
significant address bit is 0b1 or 0b0.
Table 12-6 and Table
0b1, 0b0, or 0bx. [25:2] refers to bit positions of the address, not address values.
and Table 12-4.

Table 12-3. Supported 8-Bit Accesses

nPC_CE2 nPC_CE1
1 1
0 0
1 0

Table 12-4. Supported 16-Bit Accesses

nPC_CE2 nPC_CE1
1 1
1 0
1 0
0 0
Table 12-5. The SMC does not support Type 1

Table 12-5. PCMCIA Legacy Usage

nPC_CE2 nPC_CE1
0 1
1 0
Table 12-6 and Table 12-7
12-7, bit 1 and bit 0 of the address each show a value of
Copyright 2007 Cirrus Logic
A0 D15-D8 D7-D0
X Z Z
0 Z Even Byte
1 Z Odd Byte
A0 D15-D8 D7-D0
X Z Z
0 Z Even Byte
1 Z Odd Byte
Z Odd Byte Even Byte
A0 D15-D8 D7-D0
1 Odd-Byte Z
1 Z Odd-Byte
Table 12-6
, regardless of whether the least
and
DS785UM1