pt7a6525 Pericom Technology Inc, pt7a6525 Datasheet - Page 34

• Manufacturer Part Number: pt7a6525
• Description: Pt7a6525/6525l/6526 Hdlc Controller
• Manufacturer: Pericom Technology Inc

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PT0017(12/05)
Data Reception
• Interrupt Mode
Also, 2 x 32-byte FIFO buffers (receive pools) are provided for
each channel for the receive direction.
There are two different interrupt indications related to the
reception of data:
- RPF (Receive Pool Full) interrupt, indicating that a 32-byte
- RME (Receive Message End) interrupt, indicating that the
Figure 19. Reception of a Long Frame
block of data can be read from the RFIFO, and the received
reception of one message is completed, i.e., either
message is not yet complete.
Interface
RD Status
RD Counter
RMC
RME
RMC
RMC
RPF
RPF
(32 bytes)
(2 bytes)
(32 bytes)
RD
RD
RD
34
PT7A6525/6525L/6526 HDLC Controller
PT7A6525/6525L
After an interrupt has been serviced, or the received data has
been read from the RFIFO, the microprocessor must explicitly
confirm this fact by issuing an RMC (Receive Message
Complete) command.
The microprocessor must service the RPF interrupt before an
additional 32 bytes are received via the serial interface, which
would cause a Receive Data Overflow condition.
The following figure shows the reception process of a 66-byte
long frame from the Serial Interface.
b. the last part of a message having more than 32 bytes is
a. one message of less than 32 bytes, or
PT7A6526
stored in the RFIFO.
32 bytes
32 bytes
2 bytes
Serial
Interface
Data Sheet
Ver:8