MC68HC11E Motorola, MC68HC11E Datasheet - Page 237

• Manufacturer Part Number: MC68HC11E
• Description: Microcontrollers
• Manufacturer: Motorola

AN1060 — Rev. 1.0
MOTOROLA
data received for verification. No automatic verification is provided,
though the data is printed to the screen for manual verification.
Once the MCU has received this bootloaded code, the bootloader
automatically jumps to it. The small bootloaded program in turn includes
a jump to the EPROM programming routine in the boot ROM.
Refer to the previous explanation of the
for the following discussion. The host system sends the first byte to be
programmed through the COM port to the SCI of the MCU. The SCI port
on the MCU buffers one byte while receiving another byte, increasing the
throughput of the EPROM programming operation by sending the
second byte while the first is being programmed.
When the first byte has been programmed, the MCU reads the EPROM
location and sends the result back to the host system. The host then
compares what was actually programmed to what was originally sent. A
message indicating which byte is being verified is displayed in the lower
half of the screen. If there is an error, it is displayed at the top of the
screen.
As soon as the first byte is verified, the third byte is sent. In the
meantime, the MCU has already started programming the second byte.
This process of verifying and queueing a byte continues until the host
finishes sending data. If the programming is completely successful, no
error messages will have been displayed at the top of the screen.
Subroutines follow the end of the program to handle some of the
repetitive tasks. These routines are short, and the commenting in the
source code should be sufficient explanation.
Freescale Semiconductor, Inc.
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EPROM Programming Utility
Application Note
237