Z8F6421PM020SC Datasheet, PDF (204/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
184
5. Re-write the page written in step 2 to the Page Select register.
6. Write the Page Erase command 95H to the Flash Control register.
Mass Erase
The Flash memory cannot be Mass Erased by user code.
Flash Controller Bypass
The Flash Controller can be bypassed and the control signals for the Flash memory
brought out to the GPIO pins. Bypassing the Flash Controller allows faster Programming
algorithms by controlling the Flash programming signals directly.
Flash Controller Bypass is recommended for gang programming applications and large
volume customers who do not require in-circuit programming of the Flash memory.
Refer to the document entitled Third-Party Flash Programming Support for Z8 Encore!^®
for more information on bypassing the Flash Controller. This document is available for
download at www.zilog.com.
Flash Controller Behavior in Debug Mode
The following changes in behavior of the Flash Controller occur when the Flash Control-
ler is accessed using the On-Chip Debugger:
• The Flash Write Protect option bit is ignored.
• The Flash Sector Protect register is ignored for programming and erase operations.
• Programming operations are not limited to the page selected in the Page Select
register.
• Bits in the Flash Sector Protect register can be written to one or zero.
• The second write of the Page Select register to unlock the Flash Controller is not
necessary.
• The Page Select register can be written when the Flash Controller is unlocked.
• The Mass Erase command is enabled through the Flash Control register.
Caution:
For security reasons, flash controller allows only a single page to be
opened for write/erase. When writing multiple flash pages, the flash con-
troller must go through the unlock sequence again to select another page.
PS019915-1005
Flash Memory