MPC563XM Reference Manual, Rev. 1
1202
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
Figure 26-38. DSPI usage in the TSB Configuration
The same constraints applied to DSI are valid to TSB, but the frame size and the Delay After Transfer value
(t
DT
). The TSB configuration allows from 4 to 32 bits frame size to be used, and t
DT
can be programmable
to a minimum of 1xT
SCK
, allowing a programmable inter-message gap. See
for details on programming the t
DT
values.
The time between the negation of the CS at the end of one frame to the assertion of CS at the next frame
is defined by: T
DT
= P
DT
* DT / f
sys,
but delayed until the next active edge of T
SCK
. The gap is only be
whole period of TSCK and the PDT and DT fields of the specific DSPI_CTAR0-7 register select the delay
after transfer. Some values will not be possible, see the reference manual for details.
Figure 26-39. TSB Downstream Frame
shows the two types of downstream frames, command frame, and data frame, used in
the TSB configuration, refer to
Section 26.5.9.1, “PCS Switch Over Timing
”, for detailed information. The Command Word can be written by software, and the
Data Word consisting of 32 bits words, from the SDR or ASDR registers. Only the downstream frame is
supported in the TSB configuration, the upstream frame can be handled by software using any available
serial input.
SOUT (Downstream Frame)
SCK
PCS
DSI
(Master)
32 Bit Data
Register
(ASDR)
32 Bit
(SDR)
Serial Data
GPIO or COMMAND
Data Writes
Parallel
Inputs
t
DT
Data Frame
Invalid
LSB
Active Phase
0
SCK
PCS
Master SOUT
t
DT
= from 1 to (PDT * DT / f
sys
) T
SCK
Invalid
Command Frame
t
DT
Command Frame = 0 to 32 bits
LSB
1
Selection Bit
Data Frame = 4 to 32 bits
(CPOL = 0)
Active Phase