MC68HC05X4 Datasheet, PDF (18/156 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Modes of Operation and Pin Descriptions
Boot
Yes
PA2 = 1
No
?
Test
PA3 = 1
No
?
Load Yes
Read serial byte
‘COUNT’
Execute
Read next serial byte
from PA0 into RAM
Last byte
No
?
Yes
PC RAMST + 1?
Execute user code
in RAM
Output contents of
user ROM on port B.
Figure 2. MC68HC05X4 bootloader flowchart
Bootloader mode
for the
MC68HC705X4
This mode is used for programming the on-board EPROM and mask
option register. In bootloader mode the operation of the device is the
same as in single chip mode, except that the vectors are fetched from
the bootloader ROM (locations $1F01 to $1FEF) instead of the EPROM.
The pin assignments are therefore identical to that of single chip mode
shown earlier. Because the addresses in the MC68HC705X4 and the
MC68HC05X4 Rev 1.0
Modes of Operation and Pin Descriptions
For More Information On This Product,
Go to: www.freescale.com
6-modes