ST STM32F101xx User Manual

RM0008 Flexible static memory controller (FSMC)
Doc ID 13902 Rev 12 533/1096
the odd byte on D15-8 and nCE1 accesses the even byte on D7-0 if A0=0 or the odd byte on
D7-0 if A0=1. The full word is accessed on D15-0 if both nCE2 and nCE1 are low.
The memory space is selected by asserting low nOE for read accesses or nWE for write
accesses, combined with the low assertion of nCE2/nCE1 and nREG.
● If pin nREG=1 during the memory access, the common memory space is selected
● If pin nREG=0 during the memory access, the attribute memory space is selected
The I/O Space is selected by asserting low nIORD for read accesses or nIOWR for write
accesses [instead of nOE/nWE for memory Space], combined with nCE2/nCE1. Note that
nREG must also be asserted low during accesses to I/O Space.
Three type of accesses are allowed for a 16-bit PC Card:
● Accesses to Common Memory Space for data storage can be either 8-bit accesses at
even addresses or 16 bit AHB accesses.
Note that 8-bit accesses at odd addresses are not supported and will not lead to the
low assertion of nCE2. A 32-bit AHB request is translated into two 16-bit memory
accesses.
● Accesses to Attribute Memory Space where the PC Card stores configuration
information are limited to 8-bit AHB accesses at even addresses.
Note that a 16-bit AHB access will be converted into a single 8-bit memory transfer:
nCE1 will be asserted low, NCE2 will be asserted high and only the even Byte on D7-
D0 will be valid. Instead a 32-bit AHB access will be converted into two 8-bit memory
transfers at even addresses: nCE1 will be asserted low, NCE2 will be asserted high
and only the even bytes will be valid.
● Accesses to I/O Space must be limited to AHB 16 bit accesses.
Table 133. 16-bit PC-Card signals and access type
nCE2 nCE1
nREG
nOE/nWE
nIORD /nIOWR
A10
A9
A7-1
A0
Space Access Type
Allowed/not
Allowed
1 0 101XXX-XX
Common
Memory
Space
Read/Write byte on D7-D0
YES
YES YES
0 1 1 0 1 X X X-X X Read/Write byte on D15-D8 Not supported
0 0 1 0 1 X X X-X 0 Read/Write word on D15-D0 YES
X0 00101X-X0
Attribute
Space
Read or Write Configuration
Registers
YES
X0 00100X-X0
Read or Write CIS (Card
Information Structure)
YES
1 0 001XXX-X1 Invalid
Attribute
Space
Read or Write (odd address) YES
0 1 0 0 1 X X X-X x Read or Write (odd address) YES

ST STM32F101xx Specifications

General

Brand	ST
Model	STM32F101xx
Category	Microcontrollers
Language	English