Internal Vs External Attribute Memory Map - SMC Networks SMC91C95 Product Manual

Internal VS External Attribute Memory Map

The Internal VS External EPROM attribute
memory decodes are shown below. This allows
the designer to not require an external EPROM
device if the single or multi-function PCMCIA card
needs less than 512 bytes of configuration
information. As can be seen in the map, if 512
bytes of CIS or less is required, the nFCS and
nFWE output
Table 7 - Attribute Memory Address Using Serial EEPROM
ATTRIBUTE
MEMORYADDRESS
0 - 3FEh
400h-7FFEh
8000h - 803Eh
Table 8 - Attribute Memory Address without Serial EEPROM
ATTRIBUTE
MEMORYADDRESS
0 - 7FFEh
8000h - 803Eh
pins of the
EXTERNAL EPROM
STORE
X
EXTERNAL EPROM
STORE
X
36
SMC91C95 need not be used (if serial EEPROM
is being used). Internal to the SMC91C95, the
memory addressing logic will allow byte or word on
odd byte address access (A0=1), the SMC91C95
will generate an arbitrary value of zero (0) since
the PCMCIA specification states that the high byte
of a word access in attribute memory is a don't
care. This allows backward compatibility to 8 bit
hosts.
INTERNAL SRAM
STORE (512 BYTES)
X
INTERNAL SRAM
STORE (512 BYTES)
CONFIGURATION
REGISTERS
X
CONFIGURATION
REGISTERS
X