W925EP01 Datasheet, PDF (10/108 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925EP01/ W925EP01FG
6. FUNCTIONAL DESCRIPTION
The W925EP01 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 W925EP01 contains on-chip 4K bytes MOVX RAM.
ROM:
The W925EP01 contains 64K bytes of main Flash EPROM (APROM) and a 4K bytes of auxiliary
Flash EPROM which allows the contents of the 64KB main Flash EPROM to be updated by the loader
program located at the 4KB auxiliary Flash EPROM.
The 64K bytes of in-system programmable Flash EPROM is for Application Program (APROM).
The 4K bytes of auxiliary Flash EPROM are for Loader Program (LDROM).
On-chip Data RAM:
The W925EP01 has 4K bytes of normal RAM which address is from 000H to FFFH. 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 4K bytes MOVX SRAM as they use different addressing modes and
separate instructions. The on-chip MOVX SRAM will be enabled by set the DME0 bit in the PMR
register. After a reset, the DME0 bit is set such that on-chip MOVX SRAM is enabled, and all MOVX
data access to internal memory spaces is from 000H to FFFH.
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 to DTMF pin.
CAS modulator:
W925EP01 provides a CAS generator, which outputs the CAS signal to the DTMF pin.
DTMF modulator:
The W925EP01 is built-in a dual tone multi-frequency generator, the signal output to DTMF pin.
Eight I/O Ports:
The W925EP01 has eight 8-bit I/O ports giving 64 lines (Port0 to Port7). Port0 to Port3 can be used as
an 8-bit general I/O port with bit-addressable; Port4 to Port7 can be used as an 8-bit general I/O port
with byte-addressable. The I/O mode of each port is controlled by PxIO registers. Port1 to Port7 have
internal pull high resistors enabled/disabled by PxH registers. Port0 is open-drain type in output mode.
TWO SERIAL I/O PORT:
The W925EP01 has two serial ports. The serial port0, through P3.0 (RxD) and P3.1 (TxD), is similar to
the serial port of the original 8051 family. The serial port1, through P4.0 (SCLK1) and P4.1 (SDATA1),
is an 8-bit synchronous serial I/O interface. The serial port0 have the enhanced features of Automatic
Address recognition and Frame Error detection.
TWO TIMERS, WATCH DOG TIMER AND DIVIDER:
The W925EP01 has two 13/16-bit timers or 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 W925EP01 has an internal comparator with one external analog signal input path VNEG (P4.2)
and an external reference input path VPOS (P4.4).
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