Z8F021ASH020SC datasheet(163/276 Pages) ZILOG

163 / 276 page

PS022815-0206

Flash Memory

Z8 Encore! XP® 4K Series

Product Specification

144

Flash Control Register Definitions

Flash Control Register

The Flash Controller must be unlocked using the Flash Control (FCTL) register before

programming or erasing the Flash memory. Writing the sequence 73H 8CH, sequentially,

to the Flash Control register unlocks the Flash Controller. When the Flash Controller is

unlocked, the Flash memory can be enabled for Mass Erase or Page Erase by writing the

appropriate enable command to the FCTL. Page Erase applies only to the active page

selected in Flash Page Select register. Mass Erase is enabled only through the On-Chip

Debugger. Writing an invalid value or an invalid sequence returns the Flash Controller to

its locked state. The Write-only Flash Control Register shares its Register File address

with the read-only Flash Status Register

FCMD—Flash Command

73H = First unlock command.

8CH = Second unlock command.

95H = Page Erase command (must be third command in sequence to initiate Page Erase).

63H = Mass Erase command (must be third command in sequence to initiate Mass Erase).

5EH = Enable Flash Sector Protect Register Access

Table 81. Flash Control Register (FCTL)

BITS

FIELD

FCMD

RESET

000

R/W

WWW

ADDR

FF8H

Z8F021ASH020SC 数据表(PDF) 163 Page - Zilog, Inc.