Application Note
AN1060 — Rev. 1.0
MOTOROLA
221
UPLOAD Utility
The UPLOAD utility subroutine transfers data from the MCU to a host
computer system over the SCI serial data link.
NOTE:
Only EPROM versions of the M68HC11 include this utility.
Verification of EPROM contents is one example of how the UPLOAD
utility could be used. Before calling this program, the Y index register is
loaded (by user firmware) with the address of the first data byte to be
uploaded. If a baud rate other than the current SCI baud rate is to be
used for the upload process, the user’s firmware must also write to the
baud register. The UPLOAD program sends successive bytes of data
out the SCI transmitter until a reset is issued (the upload loop is infinite).
For a complete commented listing example of the UPLOAD utility, refer
to
Listing 3. MC68HC711E9 Bootloader ROM
.
EPROM Programming Utility
The EPROM programming utility is one way of programming data into
the internal EPROM of the MC68HC711E9 MCU. An external 12-V
programming power supply is required to program on-chip EPROM. The
simplest way to use this utility program is to bootload a 3-byte program
consisting of a single jump instruction to the start of the PROGRAM utility
program ($BF00). The bootloader program sets the X and Y index
registers to default values before jumping to the downloaded program
(see [16] at the bottom of
Figure 3
). When the host computer sees the
$FF character, data to be programmed into the EPROM is sent, starting
with the character for location $D000. After the last byte to be
programmed is sent to the MC68HC711E9 and the corresponding
verification data is returned to the host, the programming operation is
terminated by resetting the MCU.
The number of bytes to be programmed, the first address to be
programmed, and the programming time can be controlled by the user if
values other than the default values are desired.
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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