
Philips Semiconductors
Product specification
P83C557E6/P80C557E6
Single-chip 8-bit microcontroller
1999 Mar 02
58
t
CLKL
Figure 50. External Clock Drive waveform
V
IH1
V
IH1
0.8V
t
CLK
V
IH1
0.8V
V
IH1
t
CLKH
t
CLKR
t
CLKF
2.4 V
0.45 V
2.0 V
0.8 V
NOTE:
AC inputs during testing are driven at 2.4V for a logic ‘HIGH’ and 0.45V for a logic
‘LOW’. Timing measurements are made at 2.0 V for a logic ‘HIGH’ and 0.8 V for a
logic ‘LOW’.
Figure 51. AC Testing Input/Output
2.4 V
NOTE:
The float state is defined as the point at which a port 0 pin sinks 3.2mA or
sources 400 A at the voltage test levels.
Figure 52. AC Testing, Float Waveform
2.4 V
0.45 V
0.45 V
Float
2.0 V
0.8 V
2.0 V
0.8 V
Test Points
2.0 V
0.8 V
t
PXIZ
Figure 53. External Program Memory Read Cycle
ALE
PSEN
PORT 0
PORT 2
A8–A15
A8–A15
A0–A7
A0–A7
t
AVLL
t
PXIX
t
LLAX
INSTR IN
t
PLIV
t
LHLL
t
PLPH
t
LLIV
t
PLAZ
t
LLPL
t
AVIV