z8f0822 ZiLOG Semiconductor, z8f0822 Datasheet - Page 170

• Manufacturer Part Number: z8f0822
• Description: High Performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

PS022517-0508
Byte Programming
Caution:
Follow the steps below to setup the Flash Sector Protect Register from user code:
1. Write
2. Write
3. Read and/or write the Flash Sector Protect Register which is now at Register File
4. Write
Flash Write Protection Option Bit
The Flash Write Protect option bit can block all program and erase operations from user
code. For more information, see
When the Flash Controller is unlocked, writes to Flash Memory from user code programs
a byte into the Flash if the address is located in the unlocked page. An erased Flash byte
contains all 1s (
change a Flash bit (or multiple bits) from zero to one requires a Page Erase or Mass Erase
operation.
Byte Programming is accomplished using the eZ8 CPU’s LDC or LDCI instructions.
Refer to eZ8 CPU Core User Manual (UM0128) for a description of the LDC and LDCI
instructions.
While the Flash Controller programs the Flash memory, the eZ8 CPU idles but the system
clock and on-chip peripherals continue to operate. Interrupts that occur when a Program-
ming operation is in progress are serviced once the Programming operation is complete.
To exit Programming mode and lock the Flash Controller, write
Register.
User code cannot program Flash Memory on a page that is located 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.
Follow the steps below to program the Flash from user code:
1. Write
2. Write the page of memory to be programmed to the Page Select Register.
3. Write the first unlock command
4. Write the second unlock command
address
Each memory location must not be programmed more than twice before an
erase occurs.
00H
5EH
00H
00H
FF9H
to the Flash Control Register to reset the Flash Controller.
to the Flash Control Register to select the Flash Sector Protect Register.
to the Flash Control Register to return the Flash Controller to its reset state.
to the Flash Control Register to reset the Flash Controller.
FFH
.
). The programming operation is used to change bits from 1 to 0. To
Option Bits
73H
8CH
to the Flash Control Register.
to the Flash Control Register.
on page 163.
Z8 Encore! XP
00H
Product Specification
to the Flash Control
®
F0822 Series
Flash Memory
157