Section 15 Serial I/O with FIFO (SIOF)
Rev. 2.00 Mar 09, 2006 page 641 of 906
REJ09B0292-0200
15.2.3
Transmit Shift Register (SITSR)
Bit:
15
14
13
...
3
2
1
0
...
Initial value:
—
—
—
...
—
—
—
—
R/W:
—
—
—
...
—
—
—
—
SITSR is a 16-bit register used to transmit serial data. The contents of this register are shifted in
MSB-first or LSB-first order, based on the LM bit in SIFCR, in synchronization with the rising
edge of the serial transmit clock (STCK), and output from the serial transmit data STXD pin. The
transfer data length is set by the DL bit in SICTR. The transmit mode bit (TRMD) in SIFCR
controls the LSB of the transmitted primary data or control data.
When the TRMD bit is cleared to 0 and the DL bit is cleared to 0 (8-bit data length), the lower 8
bits in the transmit data register (SITDR) are output. When the DL bit is set to 1 (16-bit data
length), all 16 bits in SITDR are output.
Setting the TRMD bit to 1 causes the LSB of the primary data to be output as 0. Performing write
access to the transmit control data register (SITCDR) in this case, if the DL bit is cleared to 0,
causes the lower 8 bits in SITDR to be output, with the LSB as 1, after which the lower 8 bits in
SITCDR are output. If the DL bit is set to 1, all 16 bits in SITDR are output, with the LSB as 1,
after which all 16 bits in SITCDR are output.
When transmit primary data with a value less than or equal to the transmit FIFO watermark bits
(TFWM3 to TFWM0) in SIFCR is transferred from SITDR to SITSR, the transmit data register
empty flag (TDRE) is set in SISTR. If output of the next primary data begins when the amount of
transmit primary data in SITDR is 0, an underrun error occurs, the transmit underrun error flag
(TERR) in SISTR is set, and an error interrupt request is sent to the INTC.
15.2.4
Transmit Data Register (SITDR)
Bit:
15
14
13
...
3
2
1
0
...
Initial value:
0
0
0
...
0
0
0
0
R/W:
W
W
W
...
W
W
W
W
SITDR is a 16-bit x 16-stage FIFO register that stores primary transmit data. Data should be
written to SITDR when the transmit data register empty flag (TDRE) is set to 1 in SISTR. If data
is written to SITDR when TDRE is 0, a SITDR overflow may occur. When transmit primary data
Содержание SH7616
Страница 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
Страница 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Страница 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Страница 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Страница 662: ...Section 14 Serial Communication Interface with FIFO SCIF Rev 2 00 Mar 09 2006 page 636 of 906 REJ09B0292 0200 ...
Страница 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Страница 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Страница 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Страница 935: ...SH7616 Hardware Manual ...