P87C554 NXP Semiconductors, P87C554 Datasheet - Page 70

• Manufacturer Part Number: P87C554
• Description: The P87C554 Single-Chip 8-Bit Microcontroller is manufactured inan advanced CMOS process and is a derivative of the 80C51microcontroller family
• Manufacturer: NXP Semiconductors

Philips Semiconductors
2002 Mar 25
WRITE TO SBUF
INSTRUCTION
PORT 0
PORT 2
INPUT DATA
OUTPUT DATA
80C51 8-bit microcontroller – 12 clock operation
16K/512 OTP/RAM, 8 channel 10-bit A/D, I
capture/compare, high I/O
CLEAR RI
PSEN
ALE
WR
CLOCK
ALE
t
AVLL
0
t
QVXH
FROM RI OR DPL
A0–A7
t
t
1
XHDV
LLAX
t
AVWL
0
t
t
XLXL
VALID
LLWL
V
CC
0.45V
–0.5
P2.0–P2.7 OR A8–A15 FROM DPH
Figure 51. External Data Memory Write Cycle
t
XHQX
2
Figure 52. External Clock Drive XTAL1
Figure 53. Shift Register Mode Timing
VALID
1
t
QVWX
0.2V
t
CHCL
0.7V
t
CC
XHDX
2
DATA OUT
CC
t
3
C, PWM,
DW
t
WLWH
–0.1
VALID
2
68
t
CLCX
4
t
CLCL
VALID
3
t
CHCX
t
CLCH
t
WHLH
t
5
WHQX
SU00009
VALID
4
A0–A7 FROM PCL
A8–A15 FROM PCH
6
VALID
5
7
VALID
6
P87C554
INSTR IN
Product data
8
VALID
SU00213
SET TI
SET RI
SU00027
7