LFDAS12XSDT Freescale Semiconductor, LFDAS12XSDT Datasheet - Page 446

• Manufacturer Part Number: LFDAS12XSDT
• Description: HARDWARE MC9S12XS 52-PIN
• Manufacturer: Freescale Semiconductor

Specifications of LFDAS12XSDT

• Module/board Type: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: -

Serial Peripheral Interface (S12SPIV5)
15.3.2.5
Read: Anytime; read data only valid when SPIF is set
Write: Anytime
446
Module Base +0x0004
Module Base +0x0005
Reset
Reset
W
W
R
R
The SPI data register is both the input and output register for SPI data. A write to this register
allows data to be queued and transmitted. For an SPI configured as a master, queued data is
transmitted immediately after the previous transmission has completed. The SPI transmitter empty
flag SPTEF in the SPISR register indicates when the SPI data register is ready to accept new data.
Received data in the SPIDR is valid when SPIF is set.
If SPIF is cleared and data has been received, the received data is transferred from the receive shift
register to the SPIDR and SPIF is set.
If SPIF is set and not serviced, and a second data value has been received, the second received data
is kept as valid data in the receive shift register until the start of another transmission. The data in
the SPIDR does not change.
If SPIF is set and valid data is in the receive shift register, and SPIF is serviced before the start of
a third transmission, the data in the receive shift register is transferred into the SPIDR and SPIF
remains set (see
If SPIF is set and valid data is in the receive shift register, and SPIF is serviced after the start of a
third transmission, the data in the receive shift register has become invalid and is not transferred
into the SPIDR (see
R15
T15
R7
T7
SPI Data Register (SPIDR = SPIDRH:SPIDRL)
0
0
7
7
Figure
R14
T14
R6
T6
0
0
6
6
Figure
Figure 15-7. SPI Data Register High (SPIDRH)
Figure 15-8. SPI Data Register Low (SPIDRL)
15-9).
S12XS Family Reference Manual, Rev. 1.11
15-10).
R13
T13
R5
T5
0
0
5
5
R12
T12
R4
T4
0
0
4
4
R11
T11
R3
T3
0
0
3
3
R10
T10
R2
T2
0
0
2
2
Freescale Semiconductor
R9
R1
T9
T1
0
0
1
1
R8
R0
T8
T0
0
0
0
0