TRF7970A: FIFO Status behavior under no-continuous mode

Sirs,

    We observed FIFO Status unchanged under no-continuous mode.

    We captured SPI log on TRF7907AEVM terminals as follows;

        MOSI:5C 00  5F 00  5C 00  5F 00  5C 00 ...  

        MISO:00 0C  00 50  50 0C  0C BE  BE 0C …

      <Explanation>

           MOSI:5Ch (read FIFO Status)

           MISO:0Ch (unread bytes=12)

           MOSI:5Fh (read FIFO)

           MISO:50h (data=50h)

           MOSI:5Ch (read FIFO Status)

           MISO:0Ch (unread bytes=12) -> Problem! (We expected 0Bh)

           MOSI:5Fh (read FIFO)

           MISO:BEh (data=BEh)

                ….

Question:

Is "FIFO Status unchanged under no-continuous mode" in specification?

We observed FIFO Status = 00h after continuous FIFO read as below.

(We observed "FIFO Status decrement by reading each byte ".)

        MOSI:5C 00 (read FIFO Status)

        MISO:00 0C (unread bytes=12)

        MOSI:7F 00 00 00 00 00 00 00 00 00 00 00 (read FIFO continuously)

        MISO:00 50 1B 1D 0E 00 00 00 00 01 46 06 (TRF7970A send 12bytes data via SPI)

        MOSI:5C 00 (read FIFO Status)

        MISO:00 00 (FIFO Status = 00h)

Our understanding of Specification of FIFO Status as below.

(rerated thread:

http://e2e.ti.com/support/wireless_connectivity/f/667/p/340702/1191228.aspx#1191228 )

FIFO status register always shows "The number of unread bytes"

 •MCU Reads data from FIFO:The value of FIFO Status decrements.

 •TRF7970A receives data from transceiver/tag : The value of FIFO Status increments.

FIFO status register always shows "how many bytes rest to transmit"

 •Write to FIFO from MCU:The value of FIFO Status register increments.

 •TRF7970A transmits data :The value of FIFO Status register decrements.

I'd appreciate if you would send us "Precise specification/behavior of FIFO Status".

(Is there any difference on FIFO Status behabior under non-continuous or continuous mode?)      

Best regards