PSB21384HV1.3 Infineon Technologies, PSB21384HV1.3 Datasheet - Page 110

• Manufacturer Part Number: PSB21384HV1.3
• Description: Telecom ICs AMuLaw/Speech CODEC w/ ST Transceiver
• Manufacturer: Infineon Technologies

Specifications of PSB21384HV1.3

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Data Sheet
The following description of the receive FIFIO operation is illustrated in figure 61 for a
RFIFO block size (threshold) of 16 and 32 bytes.
The RFIFO requests service from the microcontroller by setting a bit in the ISTAH
register, which causes an interrupt (RPF, RME, RFO). The microcontroller then reads
status information (RBCH,RBCL), data from the RFIFO and changes the RFIFO block
size (EXMR.RFBS). A block transfer is completed by the microcontroller via a receive
message complete (CMDR.RMC) command. This causes the space of the transferred
bytes being released for new data and in case the frame was complete (RME) the reset
of the receive byte counter RBC (RBCH,RBCL).
The total length of the frame is contained in the RBCH and RBCL registers (RBC11...0).
If a frame is longer than 4095 bytes, the RBCH.OV (overflow) bit will be set. The least
significant bits of RBCL contain the number of valid bytes in the last data block indicated
by RME (length of last data block
contain the number of bytes in the last data block or number of complete data blocks
respectively. If the number of bytes in the last data block is ’0’ the length of the last
received block is equal to the block size.
Table 10
Receive Byte Count with RBC11...0 in the RBCH and RBCL registers
The transfer block size (EXMR.RFBS) is 32 bytes by default. If it is necessary to react to
an incoming frame within the first few bytes the microcontroller can set the RFIFO block
size to a smaller value. Each time a CMDR.RMC or CMDR.RRES command is issued,
the RFIFO access controller sets its block size to the value specified in EXMR.RFBS, so
the microcontroller has to write the new value for RFBS before the RMC command.
When setting an initial value for RFBS before the first HDLC activities, a RRES
command must be issued afterwards.
The RFIFO can hold any number of frames fitting in the 64 bytes. At the end of a frame,
the RSTA byte is always appended.
All generated interrupts are inserted together with all additional information into a wait
line to be individually passed to the host. For example if several data blocks have been
received to be read by the host and the host acknowledges the current block, a new RPF
or RME interrupt from the wait line is immediately generated to indicate new data.
EXMR.RFBS
bits
’00’
’01’
’10’
’11’
block size
Selected
32 byte
16 byte
8 byte
4 byte
selected block size). Table 10 shows which RBC bits
data blocks in
RBC11...5
RBC11...4
RBC11...3
RBC11...2
complete
100
Number of
bytes in the last
data block in
RBC4...0
RBC3...0
RBC2...0
RBC1...0
HDLC Controller
PSB 21381/2
PSB 21383/4
2001-03-12