AN2398 Freescale Semiconductor / Motorola, AN2398 Datasheet - Page 6

• Manufacturer Part Number: AN2398
• Description: In-Circuit Programming of FLASH Memory via the Universal Serial Bus for the MC68HC908JB8
• Manufacturer: Freescale Semiconductor / Motorola

AN2398/D
6
In-Circuit Programming of FLASH Memory via the USB for the MC68HC908JB8
Figure 3
Table 1
When the JB8 is programmed only with the ICP code in place, the high byte of
the pseudo reset vector at $F7FE equals $FF. This will cause the ICP code to
continue to run in ICP mode. The user code can be programmed using the ICP
functions.
Freescale Semiconductor, Inc.
Content of $FF7D
For More Information On This Product,
Not $DC to $F7
$DC to $F7
Don’t care
shows the mode entry conditions.
shows the flow of the ICP code.
YES
Go to: www.freescale.com
INVALID USER PROGRAM
ICP_FLAG = CHECKSUM?
RESET VECTOR?
CONTINUE WITH
INITIALIZATION
ICP PROGRAM
ICP CODE
Figure 3. ICP Program Flow
Table 2. Entry Conditions
NO
NO
Not checksum
ICP_FLAG
Don’t care
$01
YES
YES
USER PROGRAM
CONTINUE WITH
USER CODE
PTA = 0?
NO
User mode
ICP mode.
Mode
MOTOROLA