C509-L_97 SIEMENS [Siemens Semiconductor Group], C509-L_97 Datasheet - Page 265

• Manufacturer Part Number: C509-L_97
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

10.4.2.4 Selection of Operating Mode 3
Mode 3 is used to execute a custom software in the external FLASH memory at any start address.
The header block, which has to be prepared and sent by the host for the activation of operating
mode 3 has the structure as shown in figure 10-24.
Figure 10-24
Header Block for Operating Mode 3
Mode 3 performs a direct program execution at a given startaddress , which is sent in the header
block. After sending the appropriate header block no further serial communication is necessary for
this mode. The block diagram for the communication between the host and the MCU in mode 3 is
shown in figure 10-25.
Figure 10-25
Operating Mode 3 Communication Structure
Note: The start address startaddress has to be greater than 200 H , because in the bootstrap
Semiconductor Group
mode the bootstrap loader overlaps the code address area of the external FLASH memory
from 0000 H to 01FF H .
10-27
Bootstrap Loader
1997-10-01
C509-L