DS2196 Dallas Semiconducotr, DS2196 Datasheet - Page 104

• Manufacturer Part Number: DS2196
• Description: T1 Dual Framer LIU
• Manufacturer: Dallas Semiconducotr

Receive a HDLC Message or a BOC
1. Enable RBOC and RPS interrupts
2. Wait for interrupt to occur
3. If RBOC=1, then follow steps 5 and 6
4. If RPS=1, then follow steps 7 through 12
5. If LBD=1, a BOC is present, then read the code from the RBOC register and take action as needed
6. If BD=0, a BOC has ceased, take action as needed and then return to step 1
7. Disable RPS interrupt and enable either RPE, RNE, or RHALF interrupt
8. Read RHIR to obtain REMPTY status a. if REMPTY=0, then record OBYTE, CBYTE, and POK
9. Repeat step 8
10. Wait for interrupt, skip to step 8
11. If POK=0, then discard whole packet, if POK=1, accept the packet 12. disable RPE, RNE, or
Transmit a HDLC Message
1. Make sure HDLC controller is done sending any previous messages and is current sending flags by
2. Enable either the THALF or TNF interrupt
3. Read THIR to obtain TFULL status a. if TFULL=0, then write a byte into the FIFO and skip to next
4. Repeat step 3
5. Wait for interrupt, skip to step 3
6. Disable THALF or TNF interrupt and enable TMEND interrupt
7. Wait for an interrupt, then read TUDR status bit to make sure packet was transmitted correctly.
Transmit a BOC
1. Write 6–bit code into TBOC
2. Set SBOC bit in TBOC=1
bits and then read the FIFO a1. if CBYTE=0 then skip to step 9 a2. if CBYTE=1 then skip to step 11
b. if REMPTY=1, then skip to step 10
RHALF interrupt, enable RPS interrupt and return to step 1.
checking that the FIFO is empty by reading the TEMPTY status bit in the THIR register
step (special case occurs when the last byte is to be written, in this case set TEOM=1 before writing
the byte and then skip to step 6) b. if TFULL=1, then skip to step 5
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