PSB3186FV14NT Infineon Technologies, PSB3186FV14NT Datasheet - Page 105

• Manufacturer Part Number: PSB3186FV14NT
• Manufacturer: Infineon Technologies

Specifications of PSB3186FV14NT

• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / Rohs Status: Not Compliant

The RFIFOD requests service from the microcontroller by setting a bit in the ISTAD
register, which causes an interrupt (RPF, RME, RFO). The microcontroller then reads
status information (RBCHD,RBCLD), data from the RFIFOD and then may change the
receive FIFO block size (EXMD.RFBS). A block transfer is completed by the
microcontroller via a receive message complete (CMDRD.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 (RBCHD,RBCLD)
The total length of the frame is contained in the RBCHD and RBCLD registers which
contain a 12 bit number (RBC11...0), so frames up to 4095 byte length can be counted.
If a frame is longer than 4095 bytes, the RBCHD.OV (overflow) bit will be set. The least
significant bits of RBCLD contain the number of valid bytes in the last data block
indicated by RME (length of last data block £ selected block size).
RBC bits 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 15
EXMD1.RFBS
’00’
’01’
’10’
’11’
The transfer block size (EXMD.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 RFIFOD block
size to a smaller value. Each time a CMDRD.RMC or CMDRD.RRES command is
issued, the RFIFOD access controller sets its block size to the value specified in
EXMD.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 RFIFOD can hold any number of frames fitting in the 64 bytes. At the end of a frame,
the RSTAD 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.
1)
Data Sheet
If RMC is omitted, then no new interrupt can be generated.
Receive Byte Count with RBC11...0 in the RBCHD/RBCLD Registers
Selected
block size
32 byte
16 byte
8 byte
4 byte
105
complete
data blocks in
RBC11...5
RBC11...4
RBC11...3
RBC11...2
Description of Functional Blocks
Number of
Table 15
bytes in the last
data block in
RBC4...0
RBC3...0
RBC2...0
RBC1...0
ISAC-SX TE
shows which
PSB 3186
2003-01-30
1)
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