PIC17C44 Datasheet, PDF (161/241 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM/ROM Microcontroller

PIC17C4X
Applicable Devices 42 R42 42A 43 R43 44
FIGURE 17-11: MEMORY INTERFACE WRITE TIMING
Q1
Q2
Q3
Q4
Q1
Q2
OSC1
ALE
OE
WR
AD<15:0>
150
addr out
151
152
154
data out
153
addr out
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
—
(address setup time)
151
TalL2adI ALE↓ to address out invalid
(address hold time)
0
—
— ns
— ns
152
TadV2wrL Data out valid to WR↓
(data setup time)
0.25Tcy - 40
—
— ns
153
TwrH2adI WR↑ to data out invalid
(data hold time)
—
0.25TCY § —
ns
154
TwrL
WR pulse width
—
0.25TCY § —
ns
*
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