Philips Semiconductors
Preliminary specification
80C51 8-bit microcontroller
8K/256 OTP, 8 channel 10 bit A/D, I
2
C, PWM,
capture/compare, high I/O, low voltage (2.7V鈥?.5V), low power
P87C552
2.4V
2.0V
Test Points
0.8V
0.45V
NOTE:
AC inputs during testing are driven at 2.4V for a logic 鈥?鈥?and 0.45V for a logic 鈥?鈥?
Timing measurements are made at 2.0V for a logic 鈥?鈥?and 0.8V for a logic 鈥?鈥?
0.8V
2.0V
SU00215
Figure 53. AC Testing Input/Output
Float
2.4V
2.0V
0.8V
2.0V
0.8V
2.4V
0.45V
0.45V
NOTE:
The float state is defined as the point at which a port 0 pin sinks 3.2mA or sources 400碌A at the voltage test levels.
SU00216
Figure 54. AC Testing Input, Float Waveform
repeated START condition
START or repeated START condition
t
RD
STOP condition
0.7 V
CC
0.3 V
CC
t
BUF
t
FD
t
RC
t
FC
t
SU;STO
0.7 V
CC
0.3 V
CC
t
SU;DAT3
t
HD;STA
t
LOW
t
HIGH
t
SU;DAT1
t
HD;DAT
t
SU;DAT2
t
SU;STA
START condition
SDA
(INPUT/OUTPUT)
SCL
(INPUT/OUTPUT)
SU00107A
Figure 55. Timing SIO1 (I
2
C) Interface
1999 Mar 30
69