50.4.2.3 FIFO Disable Operation
The FIFO disable mechanisms allow SPI transfers without using the TX FIFO or RX
FIFO. The DSPI operates as a double-buffered simplified SPI when the FIFOs are
disabled. The FIFOs are disabled separately; setting the MCR[DIS_TXF] bit disables the
TX FIFO, and setting the MCR[DIS_RXF] bit disables the RX FIFO.
The FIFO Disable mechanisms are transparent to the user and to host software; Transmit
data and commands are written to the PUSHR and received data is read from the POPR.
When the TX FIFO is disabled the TFFF, TFUF and TXCTR fields in SR behave as if
there is a one-entry FIFO but the contents of the TXFR registers and TXNXTPTR are
undefined. Likewise, when the RX FIFO is disabled, the RFDF, RFOF and RXCTR
fields in the SR behave as if there is a one-entry FIFO, but the contents of the RXFR
registers and POPNXTPTR are undefined.
50.4.2.4 Transmit First In First Out (TX FIFO) Buffering Mechanism
The TX FIFO functions as a buffer of SPI data and SPI commands for transmission. The
TX FIFO holds 4 words, each consisting of a command field and a data field. The
number of entries in the TX FIFO is device-specific. SPI commands and data are added
to the TX FIFO by writing to the DSPI PUSH TX FIFO Register (PUSHR). TX FIFO
entries can only be removed from the TX FIFO by being shifted out or by flushing the
TX FIFO.
The TX FIFO Counter field (TXCTR) in the DSPI Status Register (SR) indicates the
number of valid entries in the TX FIFO. The TXCTR is updated every time the DSPI
_PUSHR is written or SPI data is transferred into the shift register from the TX FIFO.
The TXNXTPTR field indicates which TX FIFO Entry will be transmitted during the
next transfer. The TXNXTPTR contains the positive offset from TXFR0 in number of
32-bit registers. For example, TXNXTPTR equal to two means that the TXFR2 contains
the SPI data and command for the next transfer. The TXNXTPTR field is incremented
every time SPI data is transferred from the TX FIFO to the shift register. The maximum
value of the field is equal to the maximum implemented TXFR register number and it
rolls over after reaching the maximum.
Functional Description
K53 Sub-Family Reference Manual, Rev. 6, Nov 2011
1366
Freescale Semiconductor, Inc.
Содержание K53 Series
Страница 2: ...K53 Sub Family Reference Manual Rev 6 Nov 2011 2 Freescale Semiconductor Inc...
Страница 58: ...K53 Sub Family Reference Manual Rev 6 Nov 2011 58 Freescale Semiconductor Inc...
Страница 70: ...Orderable part numbers K53 Sub Family Reference Manual Rev 6 Nov 2011 70 Freescale Semiconductor Inc...
Страница 168: ...Human machine interfaces HMI K53 Sub Family Reference Manual Rev 6 Nov 2011 168 Freescale Semiconductor Inc...
Страница 206: ...Boot K53 Sub Family Reference Manual Rev 6 Nov 2011 206 Freescale Semiconductor Inc...
Страница 218: ...Security Interactions with other Modules K53 Sub Family Reference Manual Rev 6 Nov 2011 218 Freescale Semiconductor Inc...
Страница 342: ...PMC Memory Map Register Definition K53 Sub Family Reference Manual Rev 6 Nov 2011 342 Freescale Semiconductor Inc...
Страница 362: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 362 Freescale Semiconductor Inc...
Страница 384: ...Initialization application information K53 Sub Family Reference Manual Rev 6 Nov 2011 384 Freescale Semiconductor Inc...
Страница 406: ...Application Information K53 Sub Family Reference Manual Rev 6 Nov 2011 406 Freescale Semiconductor Inc...
Страница 424: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 424 Freescale Semiconductor Inc...
Страница 514: ...Initialization application information K53 Sub Family Reference Manual Rev 6 Nov 2011 514 Freescale Semiconductor Inc...
Страница 524: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 524 Freescale Semiconductor Inc...
Страница 546: ...Restrictions on Watchdog Operation K53 Sub Family Reference Manual Rev 6 Nov 2011 546 Freescale Semiconductor Inc...
Страница 594: ...Interrupts K53 Sub Family Reference Manual Rev 6 Nov 2011 594 Freescale Semiconductor Inc...
Страница 628: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 628 Freescale Semiconductor Inc...
Страница 702: ...Flash Operation in Low Power Modes K53 Sub Family Reference Manual Rev 6 Nov 2011 702 Freescale Semiconductor Inc...
Страница 772: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 772 Freescale Semiconductor Inc...
Страница 808: ...Initialization Application Information K53 Sub Family Reference Manual Rev 6 Nov 2011 808 Freescale Semiconductor Inc...
Страница 864: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 864 Freescale Semiconductor Inc...
Страница 894: ...DAC Interrupts K53 Sub Family Reference Manual Rev 6 Nov 2011 894 Freescale Semiconductor Inc...
Страница 908: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 908 Freescale Semiconductor Inc...
Страница 920: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 920 Freescale Semiconductor Inc...
Страница 926: ...Functional Description K53 Sub Family Reference Manual Rev 6 Nov 2011 926 Freescale Semiconductor Inc...
Страница 1092: ...FTM Interrupts K53 Sub Family Reference Manual Rev 6 Nov 2011 1092 Freescale Semiconductor Inc...
Страница 1114: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 1114 Freescale Semiconductor Inc...
Страница 1156: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 1156 Freescale Semiconductor Inc...
Страница 1304: ...On The Go Operation K53 Sub Family Reference Manual Rev 6 Nov 2011 1304 Freescale Semiconductor Inc...
Страница 1334: ...USB Voltage Regulator Module Signal Descriptions K53 Sub Family Reference Manual Rev 6 Nov 2011 1334 Freescale Semiconductor Inc...
Страница 1388: ...Initialization Application Information K53 Sub Family Reference Manual Rev 6 Nov 2011 1388 Freescale Semiconductor Inc...
Страница 1514: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1514 Freescale Semiconductor Inc...
Страница 1622: ...Software restrictions K53 Sub Family Reference Manual Rev 6 Nov 2011 1622 Freescale Semiconductor Inc...
Страница 1694: ...Initialization application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1694 Freescale Semiconductor Inc...
Страница 1704: ...Functional description K53 Sub Family Reference Manual Rev 6 Nov 2011 1704 Freescale Semiconductor Inc...
Страница 1734: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1734 Freescale Semiconductor Inc...
Страница 1800: ...Application information K53 Sub Family Reference Manual Rev 6 Nov 2011 1800 Freescale Semiconductor Inc...
Страница 1822: ...K53 Sub Family Reference Manual Rev 6 Nov 2011 1822 Freescale Semiconductor Inc...