UM10850
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© NXP B.V. 2016. All rights reserved.
User manual
Rev. 2.4 — 13 September 2016
293 of 464
NXP Semiconductors
UM10850
Chapter 22: LPC5410x Serial Peripheral Interfaces (SPI0/1)
22.6.8 SPI Transmitter Data Register
The TXDAT register is written in order to send data via the SPI transmitter when control
information is not changing during the transfer (see
). That data will be sent
to the transmit shift register when it is available, and another character may then be
written to TXDAT.
Remark:
If the SPI is used with FIFO support, do not use this register to transmit data,
.
22.6.9 SPI Transmitter Control register
The TXCTL register provides a way to separately access control information for the SPI.
These bits are another view of the same-named bits in the TXDATCTL register (see
). Changing bits in TXCTL has no effect unless data is later written to the
TXDAT register. Data written to TXDATCTL overwrites the TXCTL register.
When control information needs to be changed during transmission, the TXDATCTL
register should be used (see
) instead of TXDAT. Control information can
then be written along with data.
Table 329. SPI Transmitter Data Register (TXDAT, offset 0x1C) bit description
Bit
Symbol
Description
Reset value
15:0
DATA
Transmit Data. This field provides from 4 to 16 bits of data to be transmitted.
0
31:16
-
Reserved. Only zero should be written.
NA
Table 330. SPI Transmitter Control register (TXCTL, offset 0x20) bit description
Bit
Symbol
Description
Reset value
15:0
-
Reserved. Read value is undefined, only zero should be written.
NA
16
TXSSEL0_N
Transmit Slave Select 0.
0x0
17
TXSSEL1_N
Transmit Slave Select 1.
0x0
18
TXSSEL2_N
Transmit Slave Select 2.
0x0
19
TXSSEL3_n
Transmit Slave Select 3.
0x0
20
EOT
End of Transfer.
0
21
EOF
End of Frame.
0
22
RXIGNORE
Receive Ignore.
0
23
-
Reserved. Read value is undefined, only zero should be written.
NA
27:24
LEN
Data transfer Length.
0x0
31:28
-
Reserved. Read value is undefined, only zero should be written.
NA