mc68hc705c9a Freescale Semiconductor, Inc, mc68hc705c9a Datasheet - Page 113

• Manufacturer Part Number: mc68hc705c9a
• Description: M68hc05 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Appendix A
EPROM Programming
A.1 Introduction
This section describes programming of the EPROM.
A.2 Bootloader Mode
Bootloader mode is entered upon the rising edge of RESET if the IRQ is at V
logic one. The bootloader code resides in the ROM from $3F00 to $3FEF. This program handles copying
of user code from an external EPROM into the on-chip EPROM. The bootload function does not have to
be done from an external EPROM, but it may be done from a host.
The user code must be a one-to-one correspondence with the internal EPROM addresses.
A.3 Bootloader Functions
Three pins are used to select various bootloader functions: PD5, PD4, and PD3. Two other pins, PC6 and
PC7, are used to drive the PROG LED and the VERF LED, respectively. The programming modes are
shown in
Freescale Semiconductor
Table
A-2.
RESET
PD5
0
0
0
1
MC68HC05C9A Advance Information Data Sheet, Rev. 4.1
Table A-2. Bootloader Functions
PD4
Table A-1. Operating Modes
X
V
0
0
1
SS
V
IRQ
to V
TST
DD
PD3
0
1
0
X
V
SS
TCAP
V
to V
DD
DD
Load RAM and execute
Program/verify
Verify only
Secure
Mode
Bootloader
TST
Mode
User
and the TCAP pin is at
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