Z8F0830HH020SG Datasheet, PDF (135/257 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore!^® F0830 Series
Product Specification
117
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 Flash Page Select Register identifies the
page to be erased. Only a page residing in an unprotected sector can be erased. With the
Flash Controller unlocked and the active page set, writing the value 95h to the Flash Con-
trol Register initiates the Page Erase operation. 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 com-
pletes. If the Page Erase operation is performed using the On-Chip Debugger, poll the
Flash Status Register to determine when the Page Erase operation is complete. When the
page erase is complete, the Flash Controller returns to its Locked state.
Mass Erase
Flash memory can also be mass erased using the Flash Controller, but only by using the
On-Chip Debugger. Mass erasing Flash memory sets all bytes to the value FFH. With the
Flash Controller unlocked and the mass erase successfully enabled, writing the value 63H
to the Flash Control Register initiates the Mass Erase operation. While the Flash Control-
ler 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 Status
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; instead, the control signals for Flash memory can
be brought out to the GPIO pins. Bypassing the Flash Controller allows faster row pro-
gramming algorithms by controlling the Flash programming signals directly.
Row programing is recommended for gang programming applications and large volume
customers who do not require in-circuit initial programming of Flash memory. Mass Erase
and Page Erase operations are also supported, when the Flash Controller is bypassed.
For more information about bypassing the Flash Controller, refer to Third-Party Flash
Programming Support for Z8 Encore!. This document is available for download at
www.zilog.com.
Flash Controller Behavior in Debug Mode
The following behavioral changes can be observed in the Flash Controller when the Flash
Controller is accessed using the On-Chip Debugger:
• The Flash write protect option bit is ignored.
PS025113-1212
Operation