DESCRIPTION
The devices are Single-Chip 8-Bit Microcontrollers manufactured in
an advanced CMOS process and are derivatives of the 80C51
microcontroller family. The instruction set is 100% compatible with
the 80C51 instruction set.
The devices support 6-clock/12-clock mode selection by
programming an OTP bit (OX2) using parallel programming. In
addition, an SFR bit (X2) in the clock control register (CKCON)
also selects between 6-clock/12-clock mode.
These devices have either one or two I2C interfaces, capable of
handling speeds up to 400 kbits/s (Fast I2C). They also have four
8-bit I/O ports, three 16-bit timer/event counters, a multi-source,
four-priority-level, nested interrupt structure, an enhanced UART and
on-chip oscillator and timing circuits.
The added features of the P8xC66xX2 make it a powerful
microcontroller for applications that require pulse width modulation,
high-speed I/O, I2C communication, and up/down counting
capabilities such as motor control.

FEATURES
• 80C51 Central Processing Unit
– 16 kbytes OTP (87C660X2, 87C661X2)
– 16 kbytes ROM (83C660X2, 83C661X2)
– 512 byte RAM
– Boolean processor
– Fully static operation
– Low voltage (2.7 V to 5.5 V at 16 MHz) operation
• 12-clock operation with selectable 6-clock operation (via software
or via parallel programmer)
• Memory addressing capability
– Up to 64 kbytes ROM and 64 kbytes RAM
• Power control modes:
– Clock can be stopped and resumed
– Idle mode
– Power-down mode
• CMOS and TTL compatible
• Two speed ranges at VCC = 5 V
– 0 to 30 MHz with 6-clock operation
– 0 to 33 MHz with 12-clock operation
• Parallel programming with 87C51 compatible hardware interface
to programmer
• RAM expandable externally to 64 kbytes
• Programmable Counter Array (PCA)
– PWM
– Capture/compare
• PLCC and LQFP packages
• Extended temperature ranges
• Dual Data Pointers
• Security bits (3 bits)
• Encryption array - 64 bytes
• 8/9 interrupt sources
• Four interrupt priority levels
• Four 8-bit I/O ports
• One I2C serial port interface has a selectable data transfer mode,
either 400 kB/sec Fast-mode or 100 kB/sec Standard-mode
(8xC660X2 and 8xC661X2)
• A second I2C serial port interface has the 400 kB/sec Fast
data-transfer mode only and selectable slew rate control of the
output pins (8xC661X2)
• Full-duplex enhanced UART
– Framing error detection
– Automatic address recognition
• Three 16-bit timers/counters T0, T1 (standard 80C51) and
additional T2 (capture and compare)
• Programmable clock-out pin
• Asynchronous port reset
• Low EMI (inhibit ALE, slew rate controlled outputs, and 6-clock
mode)
• Wake-up from Power Down by an external interrupt