com90c66 Standard Microsystems Corp., com90c66 Datasheet - Page 51

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

A0-A19
nSBHE
nMEMW
D0-D7
D0-D15
nTOPL
nMEMCS16
(Unlatched)
nMEMCS16
(Latched)
* For latched addresses, t1 and t2 do not apply. Please refer to Figure 21 for Latched Address
** 200nS minimum inactive time on consecutive memory writes to the COM90C66.
BALE
t4
t5
t6
t7
t9
Mode.
t1
t3
t2
t8
or
Address, nSBHE Set Up to BALE Low *
Address, nSBHE Set Up to nMEMW Low
Valid Data Set Up to nMEMW High
A17-A19 to nMEMCS16 Low (Unlatched) (128K RAM Decode)
A11-A19, BALE High to nMEMCS16 (Latched) (2K RAM Decode)
Data Hold Time from nMEMW High
nMEMW High to BALE High (Next Address)
Address, nSBHE Invalid to nMEMCS16 High
Address, nSBHE Hold after BALE Low *
t6
t5
t1
FIGURE 16 - WRITE RAM CYCLE
t3
Parameter
VALID
t2
51
t9
VALID DATA
t4
min
20
25
30
30
20
0
0
9
0
typ max units
t7
t8
**
40
25
nS
nS
nS
nS
nS
nS
nS
nS
nS