
Preliminary W79E225A/227A Data Sheet
Publication Release Date: December 14, 2007
- 5 -
Revision A2.0
1. GENERAL DESCRIPTION
The W79E225/227 is a fast, 8051/52-compatible microcontroller with a redesigned processor core that
eliminates wasted clock and memory cycles. Typically, the W79E225/227 executes instructions 1.5 to
3 times faster than that of the traditional 8051/52, depending on the type of instruction, and the overall
performance is about 2.5 times better at the same crystal speed. As a result, with the fully-static
CMOS design, the W79E225/227 can accomplish the same throughput with a lower clock speed,
reducing power consumption.
The W79E225/227 provides
256
bytes of on-chip RAM;
1/2
-KB of NVM memory Flash EPROM;
1/2
-
KB of auxiliary RAM;
four
8-bit, bi-directional and bit-addressable I/O ports; an additional
4
-bit port P4
and
2
-bit port P5;
three
16-bit timer/counters; Motion Feedback Module support;
2
UART serial ports;
1
channels of I2C with master/slave capability;
1
channels of Serial Peripheral Interface (SPI),
8
channels of
12
bit PWM with configurable dead time and
8
channels of 10-bit ADC. These peripherals
are all supported by
20
interrupt sources with
4
levels of priority.
The W79E225/227 also contains a
16/64
-KB Flash EPROM whose contents may be updated in-
system by a loader program stored in an auxiliary,
4
-KB Flash EPROM. Once the contents are
confirmed, it can be protected for security.