SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 102

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

Byte/Word Transfer bit BWT controls whether a byte or a word is moved during a PEC
service cycle. This selection controls the transferred data size and the increment step for
the modified pointer.
Increment Control field INC controls, whether one of the PEC pointers is incremented
after the PEC transfer. It is not possible to increment both pointers, however. If the
pointers are not modified (INC = ‘00’), the respective channel will always move data from
the same source to the same destination.
Note: The reserved combination ‘11’ is changed to ‘10’ by hardware. However, it is not
The PEC Transfer Count Field COUNT controls the action of a respective PEC channel.
The content of bit field COUNT selects the action to be taken at the time the request is
activated. COUNT may allow a specified number of PEC transfers, unlimited transfers,
or no PEC service at all.
Table 5-5
PEC channel action depend on the previous content of COUNT.
Table 5-5
Previous
COUNT
FF
FE
01
00
The PEC transfer counter allows service of a specified number of requests by the
respective PEC channel, and then (when COUNT reaches 00
interrupt service routine associated with the priority level. After each PEC transfer, the
COUNT field is decremented and the request flag is cleared to indicate that the request
has been serviced.
User’s Manual
H
H
H
H
… 02
recommended to use this combination.
H
summarizes, how the COUNT field, the interrupt requests flag IR, and the
Modified
COUNT
FF
FD
00
00
Influence of Bitfield COUNT
H
H
H
H
… 01
H
IR after
PEC Service
‘0’
‘0’
‘1’
(‘1’)
Action of PEC Channel
and Comments
Move a Byte/Word
Continuous transfer mode, i.e. COUNT is not
modified
Move a Byte/Word and decrement COUNT
Move a Byte/Word
Leave request flag set, which triggers
another request
No action!
Activate interrupt service routine rather than
PEC channel
5-12
Interrupt and Trap Functions
H
C164CM/C164SM
) activation of the
Derivatives
V1.0, 2002-02