W925E240 Datasheet, PDF (8/73 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925E/C240
6. FUNCTIONAL DESCRIPTION
The W925E/C240 is an 8-bit micro-controller with CID function. The 8-bit micro-control has the same
instruction set as the 8051 family, with one addition: DEC DPTR (op-code A5H, the DPTR is
decreased by 1). In addition, the W925E/C240 contains on-chip 8K bytes MOVX RAM.
ROM
There are 256K bytes EEPROM/MASK ROM. Only 128K bytes EEPROM/MASK ROM is used for
program code. The completely 256K bytes EEPROM/MASK ROM can be used for the look-up table
memory.
On-chip Data RAM
The W925E/C240 has 8K normal RAM which address is from 0000H to 1FFFH. It only can be
accessed by MOVX instruction; this on-chip RAM is optional under software control. The on-chip data
RAM is not used for executable program memory. There is no conflict or overlap among the 256 bytes
scratchpad RAM and the 8K Bytes MOVX RAM as they use different addressing modes and separate
instructions.
CID
The CID functions include the FSK decoder, CAS detector, and DTMF decoder and ring detector.
FSK Modulator
Support ITU-T V.23 and Bellcore 202 FSK transmit modulated signal.
DTMF Modulator
The W925E/C240 built-in dual tone multi-frequency generator.
I/O Ports:
The W925E/C240 has five 8-bit I/O ports giving 40 lines. Port0 to Port3 can be used as an 8-bit
general I/O port with bit-addressable. The I/O mode of each port is controlled by PxIO registers. Port1
to Port4 have internal pull high resistors enabled/disabled by PxH registers. Port0 is open-drain type in
output mode.
Serial I/O Port
The serial port, through P4.0 (SCLK) and P4.1 (SDATA), is an 8-bit synchronous serial I/O interface.
Timers
The W925E/C240 has two 13/16-bit timers or an 8 bits auto-reload timers. An independent watchdog
timer is used as a system monitor or as a very long time period timer. A divider can produce the
divider interrupt in every period of 0.5S or 0.25S.
Comparator
The W925E/C240 has an internal comparator with one external analog signal input path VNEG and an
external path VPOS or a regulator voltage for the reference input REF1.
Interrupts
The W925E/C240 provides 11 interrupt resources with two priority level, including 4 external interrupt
sources, 2 timer interrupts, 1 CID interrupt, 1 divider interrupt, 1 serial port interrupt, 1 comparator
interrupt and 1 watchdog timer interrupt.
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