Features
• Compatible with MCS-51™ Products
• 20K Bytes of One-time Programmable QuickFlash Memory
• 2.7V to 5.5V Operating Range
• Fully Static Operation: 0 Hz to 16 MHz
• Three-level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Eight Interrupt Sources
• Programmable Serial Channel
• Low-power Idle and Power Down Modes
• Interrupt Recovery from Power Down
• Hardware Watchdog Timer
8-bit
Microcontroller
with 20K Bytes
QuickFlash®
• Dual Data Pointer
• Power-off Flag
Description
The AT87LV55 is a low-voltage, high-performance CMOS 8-bit microcomputer with
20K bytes of QuickFlash one-time programmable (OTP) read only memory and 256
bytes of RAM. The device is manufactured using Atmel’s high-density nonvolatile
memory technology and is compatible with the industry standard MCS-51 instruction
set and pinout. The on-chip QuickFlash allows the program memory to be user pro-
(continued)
AT87LV55
Preliminary
Pin Configurations
PDIP
(T2) P1.0
(T2EX) P1.1
P1.2
1
2
3
4
5
6
7
8
9
40 VCC
39 P0.0 (AD0)
38 P0.1 (AD1)
37 P0.2 (AD2)
36 P0.3 (AD3)
35 P0.4 (AD4)
34 P0.5 (AD5)
33 P0.6 (AD6)
32 P0.7 (AD7)
31 EA/VPP
P1.3
P1.4
P1.5
TQFP
P1.6
P1.7
RST
(RXD) P3.0 10
(TXD) P3.1 11
(INT0) P3.2 12
(INT1) P3.3 13
(T0) P3.4 14
(T1) P3.5 15
(WR) P3.6 16
(RD) P3.7 17
XTAL2 18
30 ALE/PROG
29 PSEN
28 P2.7 (A15)
27 P2.6 (A14)
26 P2.5 (A13)
25 P2.4 (A12)
24 P2.3 (A11)
23 P2.2 (A10)
22 P2.1 (A9)
21 P2.0 (A8)
P1.5
P1.6
1
2
3
4
5
6
7
8
9
33 P0.4 (AD4)
32 P0.5 (AD5)
31 P0.6 (AD6)
30 P0.7 (AD7)
29 EA/VPP
P1.7
RST
(RXD) P3.0
NC
XTAL1 19
28 NC
GND 20
(TXD) P3.1
(INT0) P3.2
(INT1) P3.3
27 ALE/PROG
26 PSEN
25 P2.7 (A15)
24 P2.6 (A14)
23 P2.5 (A13)
PLCC
(T0) P3.4 10
(T1) P3.5 11
P1.5
P1.6
P1.7
7
8
9
39 P0.4 (AD4)
38 P0.5 (AD5)
37 P0.6 (AD6)
36 P0.7 (AD7)
35 EA/VPP
34 NC
RST 10
(RXD) P3.0 11
NC 12
(TXD) P3.1 13
(INT0) P3.2 14
(INT1) P3.3 15
(T0) P3.4 16
(T1) P3.5 17
33 ALE/PROG
32 PSEN
31 P2.7 (A15)
30 P2.6 (A14)
29 P2.5 (A13)
Rev. 1609A–04/00
1