Z8 Encore!® Motor Control Flash MCUs
Product Specification
216
8. Write 00hto the Flash Control Register to lock the Flash Controller.
Page Erase
Flash memory can be erased one page (512 bytes) at a time. Page-erasing Flash memory
sets all bytes in that page to the value FFh. The Page Select Register identifies the page to
be erased. While the Flash Controller executes the Page Erase operation, the eZ8 CPU
idles, but the system clock and on-chip peripherals continue to operate. The eZ8 CPU
resumes operation after the Page Erase operation completes. Interrupts that occur when
the Page Erase operation is in progress are serviced after the Page Erase operation is com-
plete. When the Page Erase operation is complete, the Flash Controller returns to its
locked state. Only pages located in unprotected sectors can be erased.
The proper steps to perform a Page Erase operation are:
1. Write 00hto the Flash Control Register to reset the Flash Controller.
2. Write the page to be erased to the Page Select Register.
3. Write the first unlock command, 73h, to the Flash Control Register.
4. Write the second unlock command 8Chto the Flash Control Register.
5. Rewrite 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
Flash memory cannot be mass-erased by user code.
Flash Controller Bypass
The Flash Controller can be bypassed and the control signals for Flash memory brought
out to the GPIO pins. Bypassing the Flash Controller allows faster programming algo-
rithms 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 Flash memory.
Refer to the ZiLOG Application Note titled Third-Party Flash Programming Support for
the Z8 Encore!® MCU (AN0117) for more information about bypassing the Flash control-
ler. 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:
Program Memory
P R E L I M I N A R Y
PS024604-1005
ZILOG [ ZILOG, INC. ]
