z8fmc16100 ZiLOG Semiconductor, z8fmc16100 Datasheet - Page 225

• Manufacturer Part Number: z8fmc16100
• Description: Z8 Encore Motor Control Flash Mcus
• Manufacturer: ZiLOG Semiconductor

PS024611-0408
Byte Programming
Flash Sector Protection
The Flash Sector Protect register can be configured to prevent sectors from being
programmed or erased. After a sector is protected, it cannot be unprotected by user code.
The Flash Sector Protect register is cleared after reset and any previously written protection
values are lost. User code must write this register in their initialization routine to enable
sector protection.
The Flash Sector Protect register shares its Register File address with the Page Select
register. The Flash Sector Protect register is accessed by writing the Flash Control register
with 5EH. After the Flash Sector Protect register is selected, it can be accessed at the Page
Select register address. When user code writes the Flash Sector Protect register, bits can
only be set to 1. Therefore, sectors can be protected, but not unprotected, through register
Write operations. The Flash Sector Protect register is deselected by writing any value to
the Flash Control register.
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 now resides at Register File
4. Write
Flash Write Protection Option Bit
The Flash Write Protect option bit can be enabled to block all program and erase operations
from user code. For more information, see
When the Flash Controller is unlocked, Writes to Program 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 ones (
change bits from 1 to 0. To change a Flash bit (or multiple bits) from 0 to 1 requires a Page
Erase or Mass Erase operation.
Byte programming can be performed using the eZ8 CPU’s LDC or LDCI instructions. For
description of the LDC and LDCI instructions, refer to eZ8 CPU User Manual (UM0128).
When the Flash Controller programs Flash memory, the eZ8 CPU idles, but system clock
and on-chip peripherals continue to operate. Interrupts which occur when a programming
operation is in progress are serviced after the programming operation is complete. To exit
programming mode and lock the Flash Controller, write
address
00h
5Eh
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.
.
FFh
). The programming operation can only be used to
Option Bits
Z8FMC16100 Series Flash MCU
on page 221.
00h
to the Flash Control register.
Product Specification
Byte Programming
213