MC68HC05B6_13 Datasheet, PDF (171/302 Pages) Freescale Semiconductor, Inc – Microcontrollers

The bootstrap program first copies part of itself into RAM, as the program cannot be executed in
ROM during verification/programming of the EPROM. It then sets the TCMP1 output to a logic high
level.
Reset
IRQ at 9V? ^N
Y
TCAP1 set? ^N
Y
Bootstrap mode
User mode
Non-user mode
A
Y
PD4 set?
N
PD3 set?
Y
N
Parallel EPROM bootstrap
Program EPROM;
parallel load;
green LED flashes
PD2 set? ^N
Y
Non-user mode
EPROM
erased?
Y
N _{Red LED on}
EPROM not erased
Green LED on
Programming OK? Y
N
Red LED on
Bad EPROM programming
Green LED on
EPROM verified
Figure C-3 Modes of operation flow chart (1 of 2)
14
MC68HC05B6
Rev. 4.1
MC68HC705B5
Freescale
C-9