W921E840 Datasheet | Winbond

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...