AN2690 Freescale Semiconductor / Motorola, AN2690 Datasheet - Page 7

• Manufacturer Part Number: AN2690
• Description: Low Frequency EEPROM Emulation on the MC68HLC908QY4
• Manufacturer: Freescale Semiconductor / Motorola

MOTOROLA
Store critical data registers that
need to be restored after reset
Disable Interrupts
Enable Interrupts
onto the STACK
Cleanup Stack
ProgEEprom()
Main Routine
Low Frequency EEPROM Emulation on the MC68HLC908QY4
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 2. Method 2 — Forcing a Reset
(Restore Internal registers from
Next instruction executed after
Store Internal Registers on to
Force Reset:
Could use STOP instruction to force reset.
This would be easiest way if STOP mode
is not required in application.
(puts PC on Stack)
Go to: www.freescale.com
(JSR ForceRst)
(X, H, A, CCR)
Call ForceRst
ProgEEprom
the Stack
STACK)
RTS
RTS
Data Registers
temporary stored
on STACK
{
{
{
{
Method 2 — Reset Forced Anywhere in Main Loop
Temporary Local
Pointer to RAM
Code into RAM
Illegal Address
Illegal Opcode
PC_MSB
PC_MSB
Variables
PC_LSB
PC_LSB
Force a RST
Copy Stack
ForceRst()
ForcedRst
CCR
A
H
X
Store
Wait?
COP
ForceRST
call
Stack
Internal
Registers
ProgEEPROM
call
Stack Pointer
AN2690
7