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83C51KB HIGH PERFORMANCE KEYBOARD MICROCONTROLLER

6.1 D.C. Characteristics

Table 7. D.C. Characteristics

Symbol

Parameter

Min

Typical

(note 1)

Max

Unit

Test

Condition

Input Low Voltage (except

EA#, RCIN, RST)

-0.5

V

Input Low Voltage RST

0

V

Input Low Voltage EA#

-0.5

0.5

V

Input Low Voltage RCIN

V

Input High Voltage (except

EA#, RCIN, RST)

0.9

V

Input High Voltage (EA#,

RST)

V

Input High Voltage RCIN

when external

clock source is

used on RCIN

Output Low Voltage (Port 0, 1,

2, 3, ALE, PSEN# except

P3.4/LED0, P3.5/LED1,

P3.6/LED2, P3.7/LED3)

0.3

0.45

1.0

(note 2,3)

Output Low Current

(P3.4/LED0, P3.5/LED1,

P3.6/LED2, P3.7/LED3 only)

613

22

mA

Output High Voltage (Port 0,

1, 2, 3, ALE, PSEN#, except

P3.0, P3.2, P3.3)

(note 4)

NOTE:

1.

2.

10mA

22mA

15mA

Ports 3:

95mA

110mA

to sink current greater than the listed test conditions.

3.

Capacitive loading on Ports 0 and 2 may cause spurious noise pulses above 0.4V to be superimposed

on the low level outputs of ALE and Ports 1, 2 and 3. The noise is due to external bus capacitance dis-

charging into the Port 0 and Port 2 pins when these pins change from 1 to 0. In applications where

capacitive loading exceeds 100pF, the noise pulses on these signals may exceed 0.8V. It may be

desirable to qualify signals with a Schmitt Trigger, or CMOS-level input logic.

4.

specification when the address lines are stabilizing.