Parity; Pos Interface Error Detection - NEC UPD98413 User Manual

4.3.5 Parity

The µPD98413 supports a parity signal for the transmit and receive interface.
(1) Transmit parity
At the transmit side of the POS interface, the µPD98413 checks a parity input by TPRTY while TENB_B or TSX is
asserted. If a parity error is detected, the µPD98413 indicates the error by the PARE bit of the APIET register.
The µPD98413 supports both odd and even parity by setting the PARM of the MDAPIT register. The default
mode is odd.
(2) Receive parity
At the receive side of the POS interface, the µPD98413 always generates a parity over RDAT[31:0] and outputs
by RPRTY.
The µPD98413 supports both odd and even parity by setting the PARM of the MDAPIR register. The default
mode is odd.

4.3.6 POS Interface Error Detection

The µPD98413 can detect some errors in the POS interface and indicates the error by the register.
(1) Transmit error
At the transmit side of the POS interface, the µPD98413 detects the following errors and indicates the error by
the APIET register.
- End Of Packet (EOP) error (Wrong order for SOP and EOP)
The µPD98413 checks EOP Signal input by TEOP at end of every packet for each port. If EOP is asserting
before Start Of Packet (SOP) is asserted, the µPD98413 is detect EOP error. If EOP error is detected, the
µPD98413 indicates the error by the APIET register.
- Parity error (POS Interface)
The µPD98413 checks a parity input by TPRTY while TENB_B is asserted. If a parity error is detected, the
µPD98413 indicates the error by the APIET register.
- Parity error (Transmit FIFO)
The µPD98413 is generate the parity when transmit packet is stored in the transmit FIFO, and check the parity
when transmit packet is take out from the transmit FIFO. If a parity error is detected, the µPD98413 indicate the
error by the APIET register.
- Packet discard error
If the µPD98413 detects packet discard, because TPA is ignore and transmit FIFO overflow occurs, the
µPD98413 indicate the error by the APIET register.
CHAPTER 4 INTERFACES
PRELIMINARY
NEC confidential and Proprietary
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