
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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