PSB7238 SIEMENS [Siemens Semiconductor Group], PSB7238 Datasheet - Page 63

• Manufacturer Part Number: PSB7238
• Description: Joint Audio Decoder-Encoder - Multimode
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Details on the Operation of the HDLC Receiver
The HDLC receive FIFO size is 2
receiver shift register while the second half is accessible from the controlling software.
The status bits pertaining to the HDLC receiver are
:
RPF
RME
RFO
RBC
RSTA
The HDLC receiver is controlled by the following bits:
Semiconductor Group
32 bytes of a frame have arrived in the receive FIFO. The frame has not yet
been completely received.
One complete frame of length less than 32 bytes, or the last part of a frame at
least 32 bytes long is stored in the receive FIFO, including the status byte. No
RPF is generated in this case. The number of bytes stored is given by RBC
bits 0 - 4.
Indicates that a frame has been lost because the FIFO was full at the reception
of the beginning of a frame.
Receive Byte Count register (RBCH, RBCL)
16 bits wide. Total number of bytes in received frame, including the status
byte.
Receive Status Register
Contains the following information:
VFR
RDO
CRC
RAB
Receive Pool Full
Receive Message End
Receive Frame Overflow
Valid Frame
Indicates whether the frame length is a multiple of 8 bit.
Receive Data Overflow
At least one byte of the frame has been lost because it could not be
stored in the FIFO.
CRC check
Correct (1) or incorrect (0).
Receive Message Aborted
By the remote station (7 consecutive ‘1’s received), yes (1) or no (0).
32 bytes. One half of the FIFO is connected to the
63
Data Sheet 1998-07-01
Functional Blocks
PSB 7238