Z8F1680SH020SG Datasheet, PDF (295/412 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F1680 Series
Product Specification
270
Caution: The byte at each Flash memory address cannot be programmed (any bits written to 0)
more than twice before an erase cycle occurs.
20.2.5. Page Erase
The 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, writing the value 95h to the Flash Control
Register initiates the Page Erase operation on the active page. 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. If the Page Erase operation is performed using the OCD, 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.
20.2.6. 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, writing the value 63H to 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 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.
20.2.7. Flash Controller Bypass
The Flash Controller can be bypassed and the control signals for Flash memory are
brought out to the GPIO pins. Bypassing the Flash Controller allows faster row
programming algorithms by controlling these 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 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, please contact Zilog Technical
Support.
PS025015-1212
PRELIMINARY
Flash Memory