p89c538nbbb NXP Semiconductors, p89c538nbbb Datasheet - Page 24

• Manufacturer Part Number: p89c538nbbb
• Description: Cmos Single-chip 8-bit Microcontrollers With Flash Program Memory
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 8. Pin Description
Table 9. Command Definitions
Note:
1997 Jun 05
P1.0–P1.7
P2.0–P2.5, P3.4, P3.5
P0.0–P0.7
P3.3
P2.7
ALE/WE
EA
P2.6, P3.7, P3.1, P3.0
V
GND
Setup auto erase/auto erase (chip)
Setup auto program/program
Reset
PA = Address of memory location to be programmed
PD = Data to be programmed at location
CC
CMOS single-chip 8-bit microcontrollers
with FLASH program memory
COMMAND
PIN NAME
4–6 MHz
A0–A7
CE
1
2
2
2
BUS CYCLES
Figure 21.
A0–A7
A8–A13, A14–A15
Q0–Q7
CE
OE
WE
V
FTEST3–FTEST0
V
GND
PP
CC
P1
RST
P3.3
XTAL2
XTAL1
VSS
SYMBOL
89C535/536/538
Erase/Programming/Verification
P2.6, P3.7, P3.1, P3.0
OPERATION ADDRESS DATA
24
Write
Write
Write
P2.0–P2.5
Command Definitions
When low voltage is applied to the V
command register default to 00H. Placing high voltage on the V
pin enables read/write operations. Device operations are selected
by writing specific data patterns into the command register. Table 2
defines these 89C535/536/538 register commands. Table 3 defines
the bus operations of 89C535/536/538.
ALE/WE
FIRST BUS CYCLE
PSEN
VDD
P2.7
P3.5
P3.4
EA
P0
Input Low Order Address Bits
Input High Order Address Bits
Data Input/Output
Chip Enable Input
Output Enable Input
Write Enable Pin
Program Supply Voltage
Flash Test Mode Selection
Power Supply Voltage (+5V)
Ground Pin
X
X
X
+5V
30H
40H
FFH
89C535/89C536/89C538
PGM COMMAND/DATA
V
LOW PULSE
0
OE
A15
A8–A13
A14
0000b
PP
FUNCTION
OPERATION ADDRESS DATA
Write
Write
Write
PP
SECOND BUS CYCLE
pin, the contents of the
Preliminary specification
X
PA
X
30H
PD
FFH
su00876
PP