
W78C32B
Publication Release Date: October 1997
- 7 -
Revision A3
DC Characteristics, continued
PARAMETER
SYM.
TEST CONDITIONS
SPECIFICATION
MIN.
TYP.
2.4
UNIT
MAX.
-
Output High Voltage
P1, P3
Output High Voltage
ALE,
PSEN
, P0
(*1)
, P2
(*1)
Input Low Voltage
P1, P3
Input Low Voltage
XTAL1, RST
(*3)
Input High Voltage
P1, P3
Input High Voltage
XTAL1, RST
(*3)
V
OH1
V
DD
= 4.5V
I
OH1
= -100
μ
A
V
DD
= 4.5V
I
OH2
= -400
μ
A
V
DD
= 4.5V
-
V
V
OH2
2.4
-
-
V
V
IL1
0
-
0.8
V
V
IL2
V
DD
= 4.5V
0
-
0.8
V
V
IH1
V
DD
= 5.5V
2.4
-
V
DD
+0.2
V
DD
+0.2
V
V
IH2
V
DD
= 5.5V
3.5
-
V
Notes:
1. P0 and P2 are in external access mode.
2. RST pin has an internal pull-down resistor of about 30K
.
3. XTAL1 is a CMOS input and RST is a Schmitt trigger input.
AC CHARACTERISTICS
The AC specifications are a function of the particular process used to manufacture the part, the
ratings of the I/O buffers, the capacitive load, and the internal routing capacitance. Most of the
specifications can be expressed in terms of multiple input clock periods (T
CP
), and actual parts will
usually experience less than a
±
20 nS variation. The numbers below represent the performance
expected from a 1.2 micron CMOS process when using 2 and 4 mA output buffers.
Clock Input Waveform
T
T
XTAL1
F
CH
CL
OP,
T
CP
PARAMETER
Operating Speed
Clock Period
Clock High
Clock Low
SYMBOL
F
OP
T
CP
T
CH
T
CL
MIN.
0
25
10
10
TYP.
-
-
-
-
MAX.
40
-
-
-
UNIT
MHz
nS
nS
nS
NOTES
1
2
3
3
Notes:
1. The clock may be stopped indefinitely in either state.
2. The T
CP
specification is used as a reference in other specifications.
3. There are no duty cycle requirements on the XTAL1 input.