MC68HC05P18 Datasheet, PDF (55/144 Pages) Freescale Semiconductor, Inc – Advance Information

Freescale Semiconductor, Inc.
Operating Modes
User Modes
6.3.2 Bootloader Mode
Bootloader mode is entered upon the rising edge of RESET if the IRQ
pin is twice the V_DD voltage and the TCAP/PD7 pin is at logic 1. In
bootloader mode, the user EEPROM and mask option register (MOR)
bytes can be erased and programmed. Figure 6-1 shows the bootloader
circuit. PTC4 determines whether erasing or programming will occur as
shown in Table 6-2.
Table 6-2. Bootloader Functions
PTC4
0
1
Function
Bulk erase/blank verify
Bulk erase/program/verify
6.3.2.1 Bulk Erase/Blank Verify
To use the bootloader circuit to bulk erase the user EEPROM, follow this
sequence:
1. Close RESET switch and PTC4 switch so these pins are held low.
2. Apply 12-V power to IRQ.
3. Release RESET.
4. Programming LED will turn on while bulk erase is occurring.
5. When bulk erase is finished, programming LED will turn off.
6. When blank verify is finished, verify LED will turn on.
7. Close RESET switch.
8. Remove 12 V from IRQ, then remove power.
MC68HC(8)05P18 — Rev. 2.0
MOTOROLA
Operating Modes
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Advance Information
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