W921C400
Description
The W921E400A/W921C400 is a single-chip CMOS 4-bit microcontroller that is a subset of W921E880A/W921C880. It features a 4-bit ALU, three multi-function timers, one channel DTMF generator, a beep tone generator, a serial I/O port and built in four by one channel comparator circuit, thus it can be easily implemented as telephone processor.
Key Features
- FEATURES Operating Voltage
- 2.8 to 5.5V operating voltage for W921E400A EPROM TYPE
- 2.4 to 5.5V operating voltage for W921C400 MASK ROM TYPE Operating Frequency
- Crystal or RC for main system clock: - Crystal for 400K, 800K, 2M, 3.58M, 4 MHz - RC up to 4 MHz Memory
- 4K × 10-bit ROM (super EPROM):
- 512 × 4-bit RAM: - 64 × 4-bit special register - 16 × 4-bit working register - 128 × 4-bit general register - 304 × 4-bit multi-purpose register Stack
- 8-bit stack pointer I/O Pins
- 13 bidirectional and individually controllable I/O lines: - P2 Port: P2.0 to P2.1 large sink current pins and open drain option - P3 Port: P3.0 to P3.3 multi-function I/O - P4 Port: P4.2 to P4.3 open drain and pull high resistor option, multi-function I/O - P5 Port: P5.1 multi-function I/O - P6 Port: P6.0 to P6.3 open drain and pull high resistor option, multi-function I/O
- 8 bidirectional I/O lines: - PA Port: PA.0 to PA.3 open drain and pull high resistor option - PB Port: PB.0 to PB.3 open drai
