z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 271

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

PS022006-0207
Caution:
Page Erase
The Flash must be programmed one word (16-bits) at a time. If a byte (8-bit) write to
Flash memory occurs, the Flash controller waits until the other byte within the word is
written before beginning the programming operation.
While the Flash Controller programs the Flash memory, Flash reads are held in wait. If the
CPU is fetching instruction from Flash, the CPU idles until the programming operation is
complete. Interrupts that occur when a programming operation is in progress are serviced
once the programming operation is complete. To exit Programming mode and lock the
Flash Controller, write
User code cannot program Flash Memory on a page that lies in a protected sector. When
user code writes memory locations, only addresses located in the unlocked page are
programmed. Memory writes outside of the unlocked page are ignored.
Each memory location must not be programmed more than twice before an erase
occurs.
Follow the steps below to program the Flash from user code:
1. Write the page of memory to be programmed to the Flash Page Select register.
2. Write the first unlock command
3. Write the second unlock command
4. Write a word to Program memory.
5. Repeat step 4 to program additional memory locations on the same page.
6. Write
The Flash memory is erased one page (2 KB) at a time. Page Erasing the Flash memory
sets all words in that page to the value FFFFH. The Flash Page Select register identifies
the page to be erased. While the Flash Controller executes the Page Erase operation, Flash
reads are held in wait. Interrupts that occur when the Page Erase operation is in progress
will be serviced once the Page Erase operation is complete. When the Page Erase opera-
tion is complete, the Flash Controller returns to its locked state. Only pages located in
unprotected sectors are erased.
The steps to perform a Page Erase operation are:
1. Write the page to be erased to the Flash Page Select register.
2. Write the first unlock command
3. Write the second unlock command
4. Write the Page Erase command
00H
to the Flash Command register to lock the Flash Controller.
00H
P R E L I M I N A R Y
to the Flash Command register.
95H
73H
73H
8CH
8CH
to the Flash Command register.
to the Flash Command register.
to the Flash Command register.
to the Flash Command register.
to the Flash Command register.
Product Specification
ZNEO
™
Flash Memory
Z16F Series
257