W921E400A Datasheet, PDF (1/53 Pages) Winbond – 4-BIT MICROCONTROLLER

W921E400A/W921C400
4-BIT MICROCONTROLLER
Table of Contents-
1. GENERAL DESCRIPTION .........................................................................................................................3
2. FEATURES.................................................................................................................................................3
3. PIN CONFIGURATION ...............................................................................................................................5
4. PIN DESCRIPTION.....................................................................................................................................6
5. BLOCK DIAGRAM ......................................................................................................................................7
6. FUNCTION DESCRIPTION........................................................................................................................8
6.1 ROM Memory Map ..............................................................................................................................8
6.2 RAM Memory Map...............................................................................................................................9
6.2.1 Special Control Register Area ....................................................................................................9
6.2.2 Stack Register Area .................................................................................................................11
6.2.3 Working Register Area.............................................................................................................12
6.3 Internal Oscillator Circuit.....................................................................................................................12
6.4 Initial State .........................................................................................................................................13
6.5 Input/Output........................................................................................................................................13
6.5.1 Normal/Special function selection of I/O...................................................................................14
6.5.2 Pull High and Open Drain Control of I/O ..................................................................................15
6.6 Serial Port ..........................................................................................................................................18
6.7 DTMF Generator................................................................................................................................20
6.8 Beep Tone Generator ........................................................................................................................22
6.9 Comparator........................................................................................................................................22
6.10 Timer/Counter ..................................................................................................................................24
6.10.1 TM0.......................................................................................................................................24
6.10.2 TM2.......................................................................................................................................26
6.10.3 TM3.......................................................................................................................................28
6.10.4 Arbitrary Waveform Generator ...............................................................................................29
6.11 Interrupt............................................................................................................................................30
6.11.1 Interrupt Control Register.......................................................................................................30
6.11.2 Interrupt Enable Flag .............................................................................................................31
Publication Release Date: July 1998
-1-
Revision A3