sak-c868p-1rr Infineon Technologies Corporation, sak-c868p-1rr Datasheet - Page 238

• Manufacturer Part Number: sak-c868p-1rr
• Description: 8 - Bit Cmos Microcontroller
• Manufacturer: Infineon Technologies Corporation

the bootstrap loader sends an Acknowledge byte (55
correctly, it will be guaranteed that both serial interfaces are working with the same baud
rate.
9.2.2
After the successful synchronization to the host, the bootstrap loader enters phase II,
during which it communicates with the host to select the desired working modes. The
detailed communication protocol is explained as follows:
9.2.2.1
The communication between the host and the bootstrap loader is done by a simple
transfer protocol. The information is sent from the host to the MCU in blocks. All the
blocks follow the specified block structure. The communication is nearly unidirectional,
that is, that the host is sending several transfer blocks and the bootstrap loader is just
confirming them by sending back single acknowledge or error bytes. The MCU itself
does not send any transfer blocks.
Figure 9-6
User’s Manual
Format Item Description
blocktype
data area
checksum
Phase II: Serial communication protocol and the working modes
Serial communication protocol
blocktype
1 byte
Basic Structure of a Bootstrap Loader Transfer Block
This byte determines how the data in the data area is
interpreted.
Implemented block types are:
00
01
02
This area contains a number of bytes which represents
the data of the block. The maximal length of data area
cannot exceed 125 bytes.
the XOR checksum of block byte and data area, sent
after the data area.
H
H
H
type "HEADER"
type "DATA"
type "END OF TRANSMISSION" (EOT)
Figure 9-6
data area
XX byte
9-8
shows the format of the transfer block.
H
) to the host. If this byte is received
The Bootstrap Loader
checksum
1 byte
V 1.0, 2003-01
C868