PIC17C4X
Applicable Devices 42 R42 42A 43 R43 44
FIGURE 17-11: MEMORY INTERFACE WRITE TIMING
Q1
Q2
Q3
Q4
Q2
Q1
OSC1
ALE
OE
151
WR
150
addr out
154
data out
AD<15:0>
addr out
152
153
TABLE 17-11: MEMORY INTERFACE WRITE REQUIREMENTS
Parameter
No.
Sym
Characteristic
Min
Typ†
Max Units Conditions
150
TadV2alL
AD<15:0> (address) valid to ALE↓
0.25Tcy - 30
—
—
ns
(address setup time)
151
152
153
154
TalL2adI
TadV2wrL
TwrH2adI
TwrL
ALE↓ to address out invalid
(address hold time)
0
—
—
—
ns
Data out valid to WR↓
(data setup time)
0.25Tcy - 40
—
—
—
ns
ns
ns
WR↑ to data out invalid
(data hold time)
—
—
0.25TCY §
0.25TCY §
WR pulse width
*
These parameters are characterized but not tested.
†
Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
§
This specification is guaranteed by design.
1996 Microchip Technology Inc.
DS30412C-page 161
MICROCHIP [ MICROCHIP ]
