W921E840A Datasheet, PDF (1/58 Pages) Winbond – 4-BIT MICROCONTROLLER

W921E840A/W921C840
4-BIT MICROCONTROLLER
Table of Contents-
1. GENERAL DESCRIPTION .........................................................................................................................3
2. FEATURES.................................................................................................................................................3
3. PIN CONFIGURATIONS.............................................................................................................................6
40-pin DIP..................................................................................................................................................6
48-pin QFP.................................................................................................................................................7
4. PIN DESCRIPTION.....................................................................................................................................9
5. BLOCK DIAGRAM ....................................................................................................................................10
6. FUNCTIONAL DESCRIPTION .................................................................................................................11
6.1 ROM Memory Map ...........................................................................................................................11
6.2 RAM Memory Map............................................................................................................................12
6.2.1 Special Control Register Area .................................................................................................12
6.2.2 Stack Register Area ................................................................................................................14
6.2.3 Working Register Area............................................................................................................15
6.3 Internal Oscillator Circuit ...................................................................................................................15
6.4 Initial State ........................................................................................................................................16
6.5 Input/Output ......................................................................................................................................17
6.5.1 Normal/Special Function Selection of I/O ................................................................................17
6.5.2 Pull High and Open Drain Control of I/O .................................................................................19
6.6 Serial Port .........................................................................................................................................21
6.7 DTMF Generator...............................................................................................................................24
6.8 Beep Tone Generator .......................................................................................................................25
6.9 D/A Converter ...................................................................................................................................26
6.10 Comparator.....................................................................................................................................27
6.11 Timer/Counter .................................................................................................................................28
6.11.1 TM0......................................................................................................................................28
6.11.2 TM1......................................................................................................................................30
6.11.3 TM2......................................................................................................................................32
6.11.4 TM3......................................................................................................................................34
6.11.5 Arbitrary Waveform Generator ..............................................................................................35
Publication Release Date: July 1999
-1-
Revision A3