Z8 Encore! XP® 4K Series
Product Specification
143
value 63Hto the Flash Control register initiates the Mass Erase operation. While the Flash
Controller executes the Mass Erase operation, the eZ8 CPU idles but the system clock and
on-chip peripherals continue to operate. Using the On-Chip Debugger, poll the Flash Sta-
tus register to determine when the Mass Erase operation is complete. When the Mass
Erase is complete, the Flash Controller returns to its locked state.
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 Row Program-
ming algorithms by controlling the Flash programming signals directly.
Row programming is recommended for gang programming applications and large volume
customers who do not require in-circuit initial programming of the Flash memory. Page
Erase operations are also supported when the Flash Controller is bypassed.
Please refer to the document entitled Third-Party Flash Programming Support for Z8
Encore!® for more information about 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.
For security reasons, the flash controller allows only a single page to be opened for
write/erase. When writing multiple flash pages, the flash controller must go through the
unlock sequence again to select another page.
Caution:
PS022815-0206
Flash Memory
ZILOG [ ZILOG, INC. ]
