Philips Semiconductors

Preliminary specification

83C748/87C748

80C51 8-bit microcontroller family

2K/64 OTP/ROM, low pin count

1999 Apr 15

6

AC ELECTRICAL CHARACTERISTICS

16MHz CLOCK

VARIABLE CLOCK

SYMBOL

PARAMETER

MIN

MAX

MIN

MAX

UNIT

Oscillator frequency:

3.5

12

MHz

3.5

16

MHz

External Clock (Figure 1)

High time

20

20

ns

Low time

20

20

ns

Rise time

20

20

ns

Fall time

20

20

ns

NOTES:

noted.

2. Load capacitance for ports = 80pF.

EXPLANATION OF THE AC SYMBOLS

Each timing symbol has five characters. The first character is always

‘t’ (= time). The other characters, depending on their positions,

indicate the name of a signal or the logical status of that signal. The

designations are:

C – Clock

D – Input data

H – Logic level high

L – Logic level low

Q – Output data

T – Time

V – Valid

X – No longer a valid logic level

Z – Float

0.45V

SU00297

Figure 1. External Clock Drive

ROM CODE SUBMISSION

When submitting ROM code for the 83C748, the following must be specified:

1. 2k byte user ROM data

ADDRESS

CONTENT

BIT(S)

COMMENT

0000H to 07FFH

DATA

7:0

User ROM Data