peb20560 Infineon Technologies Corporation, peb20560 Datasheet - Page 62

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

Semiconductor Group
RR-Frames
RR-frames are processed automatically and are not stored in RFIFO.
When a RR-frame with poll bit set (control field = xxx10001) is received, it is interpreted
as a request to transmit direct data.
Depending on the status of the XFIFO an I-frame (data available) or a RR-response (no
data available) is issued.
This behavior guarantees minimum response times and supports a fast cyclical polling
of signaling data in a point-to-multi-point configuration.
A RR-frame with poll bit = 0 is interpreted as an acknowledgment for a previously
transmitted I-frame: the XFIFO is cleared, a XPR interrupt is emitted, no response is
generated.
The polling of a frame can be repeated an unlimited number of times until the frame is
acknowledged. Depending on the status of the bit MODE:AREP (auto repeat), the
transmission is repeated without or with the intervention of the CPU (XMR interrupt). The
auto repeat mode must not be selected, when the frame length exceeds 32 bytes. In
DMA mode, when using the auto repeat mode, the control response will not be
compatible to the PBC.
I-Frames
When an I-frame is received in auto-mode the first data byte is interpreted as a command
byte according to the PEB 2050 (PBC) protocol.
Depending on the value of the command byte one of the following actions is performed.
Table 2-7 Auto-Mode Command Byte Interpretation
Command Byte =
1. Data Byte
00 - 9F
B0 - CF
F0 - FF
A0-AF
D0 - EF
H
H
H
H
H
Stored in
RFIFO
yes
no
no
no
Interrupt
RPF, RME Response generation
no
XPR
no
2-16
Additional Activities
when poll bit set
Response generation
when poll bit set
I-frame with
XFIFO-Data
Response generation
when poll bit set,
reset XFIFO
Response generation
when poll bit set
Functional Block Description
Condition
–
–
Command
XPD executed
Command
XPD executed
Command
XPD not
executed
PEB 20560
2003-08