W78E51B_05 Datasheet, PDF (15/25 Pages) Winbond – 8-BIT MICROCONTROLLER

W78E51B
DC Characteristics, continued
PARAMETER
Input Low Voltage
(Except RST)
Input Low Voltage
RST ^(*4)
Input Low Voltage
XTAL1 ^(*4)
Input High Voltage
(Except RST)
Sink Current
P1, P2, P3, P4
Input High Voltage
RST ^(*4)
Input High Voltage
XTAL1 ^(*4)
Sink Current
P0, ALE, PSEN ^(*3)
Source Current
P1, P2, P3, P4
Source Current
P0, ALE, PSEN ^(*3)
SYMBOL TEST CONDITIONS
VIL1
VDD = 4.5V
SPECIFICATION
MIN.
MAX.
0
0.8
UNIT
V
VIL2
VDD = 4.5V
0
0.8
V
VIL3
VDD = 4.5V
0
0.8
V
VIH1
ISK1
VIH2
VDD = 4.5V
VDD = 4.5V
Vs = 0.45V
VDD = 4.5V
VIH3
ISK2
ISR1
ISR2
VDD = 4.5V
VDD = 4.5V
Vs = 0.45V
VDD = 4.5V
V_S = 2.4V
VDD = 4.5V
V_s = 2.4V
2.4
VDD +0.2
V
4
12
mA
0.67
VDD
VDD +0.2
V
0.67
VDD
VDD +0.2
V
8
16
mA
-100
-250
uA
-8
-14
mA
Notes:
*1. Pins P1, P2 and P3 source a transition current when they are being externally driven from 1 to 0. The transition current
reaches its maximum value when VIN is approximately 2V.
*2. RST pin has an internal pull-down resistor.
*3. P0, ALE, PSEN are in the external access memory mode.
*4. XTAL1 is a CMOS input and RST is a Schmitt trigger input.
8.3 A.C. 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 (TCP), and actual parts will usually
experience less than a ±20 nS variation. The numbers below represent the performance expected
from a 0.6micron CMOS process when using 2 and 4 mA output buffers.
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Publication Release Date: Sep. 6, 2005
Revision A7