AN2295 Freescale Semiconductor / Motorola, AN2295 Datasheet - Page 7

• Manufacturer Part Number: AN2295
• Description: Developers Serial Bootloader for M68HC08 and HCS08 MCUs
• Manufacturer: Freescale Semiconductor / Motorola

If the MCU is operating at the correct data rate (no calibration is possible or needed and the MCU clock
is crystal driven), the PC can send an ACK immediately, skipping the calibration phase entirely. See
Figure
Freescale Semiconductor
5.
CALIBRATION SUCCESSFUL
CALIBRATION UNSUCCESSFUL
OR ONLY ROUGH CORRECTION DONE
ACK IS SENT AT CORRECT DATARATE
FROM NOW ON, THE COMMUNICATION IS AT THE CORRECTLY SPECIFIED DATA RATE
MCU
Developer’s Serial Bootloader for M68HC08 and HCS08 MCUs, Rev. 6
Figure 4. Start-Up Communication with Calibration
ACK IS SENT AT UNCERTAIN DATA RATE
ONLY 0XFC CHARACTER CAN BE RECEIVED
PC
FC Protocol Description
7