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Deserial Serial Peripheral Interface (DSPI)
MPC5566 Microcontroller Reference Manual, Rev. 2
20-58
Freescale Semiconductor
20.4.7.2
Classic SPI Transfer Format (CPHA = 1)
This transfer format shown in
is used to communicate with peripheral SPI slave devices that
require the first SCK
x
edge before the first data bit becomes available on the slave SOUT pin. In this
format the master and slave devices change the data on their SOUT
x
pins on the odd-numbered SCK
x
edges and sample the data on their SIN
x
pins on the even-numbered SCK
x
edges.
Figure 20-35. DSPI Transfer Timing Diagram (MTFE = 0, CPHA = 1, FMSZ = 8)
The master initiates the transfer by asserting the PCS
x
signal to the slave. After the
t
CSC
delay has elapsed,
the master generates the first SCK
x
edge and at the same time places valid data on the master SOUT
x
pin.
The slave responds to the first SCK
x
edge by placing its first data bit on its slave SOUT
x
pin.
At the second edge of the SCK
x
the master and slave sample their SIN
x
pins. For the rest of the frame the
master and the slave change the data on their SOUT
x
pins on the odd-numbered clock edges and sample
their SIN
x
pins on the even-numbered clock edges. After the last clock edge occurs a delay of t
ASC
is
inserted before the master negates the PCS
x
signal. A delay of t
DT
is inserted before a new frame transfer
can be initiated by the master.
For CPHA = 1 the master EOQF and TCF and slave TCF are set at the last serial clock edge (edge 16) of
. For CPHA = 1 the master and slave RXCTR counters are updated on the same clock edge.
Slave (CPHA = 1): TCF is set and RXCTR counter is updated at
last SCK edge of frame (edge 16)
SCK
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
(CPOL = 0)
PCSx / SS
t
ASC
SCK
(CPOL = 1)
Master and slave
sample
Master SOUT/
Slave SIN
Master SIN/
Slave SOUT
Bit 6
Bit 1
Bit 5
Bit 2
Bit 4
Bit 3
Bit 3
Bit 4
Bit 2
Bit 5
Bit 1
Bit 6
LSB
MSB
MSB
LSB
t
DT
t
CSC
MSB first (LSBFE = 0):
LSB first (LSBFE = 1):
t
CSC
= PCS to SCK delay.
t
ASC
= After SCK delay.
t
DT
= Delay after transfer (minimum CS negation time).
Master (CPHA = 1): TCF and EOQF are set and RXCTR counter
is updated at last SCK edge of frame (edge 16)
16
Summary of Contents for MPC5566
Page 81: ...Introduction MPC5566 Microcontroller Reference Manual Rev 2 1 24 Freescale Semiconductor...
Page 135: ...Signal Description MPC5566 Microcontroller Reference Manual Rev 2 2 54 Freescale Semiconductor...
Page 189: ...Reset MPC5566 Microcontroller Reference Manual Rev 2 4 20 Freescale Semiconductor...
Page 603: ...Flash Memory MPC5566 Microcontroller Reference Manual Rev 2 13 38 Freescale Semiconductor...
Page 609: ...SRAM MPC5566 Microcontroller Reference Manual Rev 2 14 6 Freescale Semiconductor...
Page 1073: ...MPC5566 Microcontroller Reference Manual Rev 2 22 36 Freescale Semiconductor...
Page 1185: ...Nexus MPC5566 Microcontroller Reference Manual Rev 2 25 92 Freescale Semiconductor...