com90c66 Standard Microsystems Corp., com90c66 Datasheet - Page 69

• Manufacturer Part Number: com90c66
• Description: Arcnet Controller/transceiver With At Interface And On-chip Ram Corporation
• Manufacturer: Standard Microsystems Corp.

nMEMR,nMEMW
BALE
A13*
nENROM
A19
A18
A17
A16
A15
A14
A13
A12
A11
A19
A18
A17
A16
A15
A14
nMEMR
BALE
* In I/O 16K X 8 Mode, A13 is a Don't Care
Transparent
Latch
Transparent
Modified Version of Pages 16 and 41 for Rev. D COM90C66 Only.
Latch
TABLE 13 - IOCHRDY and nOWS Signal Behavior
STATE
WAIT
BIT
0
1
Transparent
Transparent
Latch
Latch
FIGURE 4 - MEMORY SELECTOR
FIGURE 5 - PROM SELECTOR
Negated for Two to Three
XTAL1 Clocks
IOCHRDY
logic "1"
MEMORY SELECT
PROM DECODE
Comparator
Comparator
69
Activated on
Access
logic "1"
nOWS
Decoder
Decoder
5 to 9
5 to 7
MS4
MS3
MS2
MS1
MS0
MS4
MS3
MS2
MS1
MS0