MC68HC705C9A_1 Datasheet, PDF (152/157 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
General Release Specification
A.3 Bootloader Mode
RESET
Table A-1. Operating Modes
IRQ
TCAP
V_SS to V_DD
V_TST
V_SS to V_DD
V_DD
Mode
User
Bootloader
Bootloader mode is entered upon the rising edge of RESET if the IRQ is
at V_TST and the TCAP pin is at 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.4 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 Table A-2.
Table A-2. Bootloader Functions
PD5
PD4
PD3
Mode
0
0
0
Program/Verify
0
0
1
Verify Only
0
1
0
Load RAM and Execute
1
X
X
Secure
MC68HC705C9A — Rev. 2.0
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