com90c66 Standard Microsystems Corp., com90c66 Datasheet - Page 54

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

nMEMR
nPROM **
nTOPL
IOCHRDY
A0-A19
BALE
* For latched addresses, t1 and t2 do not apply. Please refer to Figure 21 for Latched Address
** All PROM accesses are 8-bit only, ROM should use nMEMR as nOE signal and PROM as nCS.
Mode.
t1
t2
t3
t4
t5
t6
t7
t8
t9
t10
nMEMR High to nTOPL High
Address Set Up to BALE Low *
Address Hold after BALE Low *
Address, Set Up to nMEMR Low
nMEMR Low to nPROM Low
nMEMR Low to nTOPL Low
nMEMR Low to IOCHRDY Low
IOCHRDY Low Pulse Width
nMEMR High to nPROM HIgh
nMEMR High to BALE High (Next Address)
Parameter
FIGURE 19 - READ PROM CYCLE
t1
t3
VALID
t4
t6
t2
t5
54
t7
min
100
20
20
50
30
0
0
0
0
0
typ
max
165
25
30
20
15
30
t10
t9
units
t8
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS