peb20560 Infineon Technologies Corporation, peb20560 Datasheet - Page 322

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

5.1.1.6.12 Receive Status Register (RSTA)
Access: read
Reset value: xx
RSTA always displays the momentary state of the receiver. Because this state can differ
from the last entry in the FIFO it is reasonable to always use the status bytes in the FIFO.
VFR
Note: Shorter frames are not reported.
RDO
CRC
RAB
HA1…0
Semiconductor Group
bit 7
VFR
In combination with the bit STAR:RFR multiple frames can be read out of the
RFIFO without interrupt control.
Valid Frame.
Indicates whether the received frame is valid (‘1’) or not (‘0’ invalid).
A frame is invalid when
– its length is not an integer multiple of 8 bits (n × 8 bits), e.g. 25 bit,
– its is to short, depending on the selected operation mode:
– a frame was aborted (note: VFR can also be set when a frame was
Receive Data Overflow.
A ‘1’ indicates, that a RFIFO-overflow has occurred within the actual frame.
CRC-Compare Check.
0: CRC check failed, received frame contains errors.
1: CRC check o.k., received frame is error free.
Receive message Aborted.
When ‘1’ the received frame was aborted from the transmitting station.
According to the HDLC-protocol, this frame must be discarded by the CPU.
High byte Address compare.
In operating modes which provide high byte address recognition, the
SACCO compares the high byte of a 2-byte address with the contents of two
individual programmable registers (RAH1, RAH2) and the fixed values FEH
and FCH (group address). Depending on the result of the comparison, the
following bit combinations are possible:
10…RAH1 has been recognized.
RDO
H
auto-mode/non-auto mode (2-byte address field): 4 bytes
auto-mode/non-auto mode (1-byte address field): 3 bytes
transparent mode 1:
transparent mode 0:
aborted)
CRC
RAB
5-79
HA1
HA0
Description of Registers
3 bytes
2 bytes
C/R
PEB 20560
bit 0
2003-08
LA