Holtek BC45B4523, Руководство пользователя, Страница: 16 / 96

Rev. 1.20 16 October 28, 2020
BC45B4523
• PrimaryStatus Register
This register contains flags for indicating the status of modem, interrupt and FIFO.
Address Bit 7 6 5 4 3 2 1 0
0x03
Name — ModemState[2:0] IRQ ERR HiAlert LoAlert
Type — R R R R R
Reset Value — 0 0 0 0 1 0 1
Bit 7 Unimplemented, read as “0”
Bit 6~4 ModemState[2:0] : Indicate the state of RX, TX and FIFO
000: Idle – No operation, neither the transmitter nor the receiver is in operation
001: TxSOF – The transmitter is transmitting “Start of Frame” pattern
010: TxData – The transmitter is transmitting data from FIFO or CRC
011: TxEOF – The transmitter is transmitting “End of Frame” pattern
100: RxPrepare – Receiver circuitry is initialized at this state and wait for time period defined by the
RxWait and BitPhase bits before starting to receive data
101: RxAwaiting – The receiver starts and is waiting for RX Start of Frame from tag
110: Receiving – The receiver is receiving data
Bit 3 IRQ : Interrupt request indication
If there are one or more interrupt requests in InterruptFlag register, the IRQ flag will be set to 1.
Bit 2 ERR : Error indication
If one or more errors occur in the Error register (Sector0-0x0A), the ERR flag will be set to 1.
Bit 1
HiAlert
: FIFO HiAlert warning flag
If FIFOLength ≥ 64-Waterlevel, the HiAlert flag will be set to 1.
Bit 0 LoAlert : FIFO LoAlert warning flag
If FIFOLength ≤ Waterlevel, the LoAlert flag will be set to 1.
• FIFOLength Register
This register indicates the number of data remaining in the FIFO buffer.
Address Bit 7 6 5 4 3 2 1 0
0x04
Name — FIFOLength[6:0]
Type — R
Reset Value — 0 0 0 0 0 0 0
Bit 7 Unimplement, read as “0”
Bit 6~0 FIFOLength[6:0] : Indicates the number of data remaining in the FIFO buffer
• SecondaryStatus Register
This register contains the status flags and values related to timers, CRC and receiver status.
Address Bit 7 6 5 4 3 2 1 0
0x05
Name Trunning RF_Det CRCReady EMD_Det SubC_Det RxLastBit[2:0]
Type R R R R R R
Reset Value 0 0 1 0 0 0 0 0
Bit 7 Trunning : Timer running state indication
If Timer is running, Trunning will be set to 1. The value in TimerValue register decreases at the rate of
timer clock, prescaling from 13.56MHz by TPreScaler bit field.