peb20560 Infineon Technologies Corporation, peb20560 Datasheet - Page 61

• Manufacturer Part Number: peb20560
• Description: Dsp Oriented Pbx Controller Doc
• Manufacturer: Infineon Technologies Corporation

Auto-Mode (MODE:MDS1,MDS0 = 00)
Characteristics: HDLC formatted, NRM-type protocol, 1-byte/2-byte address field,
address recognition, any message length, automatic response generation for RR- and
I-frames, window size 1.
The auto-mode is optimized to communicate with a group controller following a NRM-
(Normal Response Mode) type protocol. Its functionality guarantees a minimum
response time and avoids the interruption of the CPU in many cases.
The SACCO auto-mode is compatible to a PEB 2050 (PBC) behavior in secondary
mode.
Following the PBC-conventions, two data types are supported in auto-mode.
Table 2-5 Auto-Mode Data Types
Data Types
Direct data
Prepared data
Note: In many applications only direct data is used, nevertheless both data types are
Receive Direction
In auto-mode the SACCO provides address recognition for 2- and 1-byte address fields.
The auto-mode protocol is only applied when RAL1 respectively RAH1/RAL1 match.
With any other matching combination, the frame is transferred transparently into the
RFIFO and an interrupt (RPF or RME) is issued.
If no address match occurs, the frame is skipped. The auto-mode protocol processes
RR- and I-frames automatically. On the reception of any other frame type an
EHC-interrupt (extended HDLC frame) is generated. No data is stored in the RFIFO but
due to the internal hardware structure the HDLC-control field is temporarily stored in
register RHCR. In the PBC-protocol an extended HDLC-frame does not contain any
data.
Table 2-6 HDLC-Control Field in Auto-Mode
HDLC-Control Byte
xxxP xxx0
xxxP xx01
xxxx xx11
Semiconductor Group
supported because of compatibility reasons.
Meaning
Data exchanged in normal operation mode between the
local µP and the group controller, typically signaling data.
Data request by or send to the group controller for
maintenance purposes.
Frame Type
I-frame
RR-frame
Extended HDLC-frame
2-15
Functional Block Description
PEB 20560
2003-08