NXP Semiconductors MPC5644A, Reference Manual, Page: 1333 / 1735

Deserial Serial Peripheral Interface (DSPI)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 1333
30.10.4 Delay settings
Table 30-46 shows the values for the Delay after Transfer (t
DT
) and CS to SCK Delay (T
CSC
) that can be
generated based on the prescaler values and the scaler values set in the DSPI_CTAR registers. The values
calculated assume a 100 MHz system frequency.
Table 30-46 does not apply for TSB Continuous mode.
30.10.5 DSPI Compatibility with the QSPI of the MPC500 MCUs
Table 30-47 shows the translation of commands written to the TX FIFO command halfword with
commands written to the Command Ram of the MPC500 family MCUs QSPI. The table illustrates how to
configure the DSPI_CTAR registers to match the default cases for the possible combinations of the
MPC500 Family QSPI Control Bits in its Command RAM. The defaults for QSPI are based on a system
clock of 40MHz. All delay variables below will generate the same delay, or as close a possible, from the
DSPI 100MHz system clock that an QSPI would generate from its 40MHz system clock. For other system
clock frequencies, the customer can recompute the values using
Section 30.10.4, Delay settings ”.
• For BITSE = 0

8 bits per transfer
• For DT = 0

0.425

s delay: For this value, the closest value in the DSPI is 0.480

s
Table 30-46. Delay values
Delay prescaler values
1 3 5 7
Delay
sc
aler
valu
e
s
2 20.0 ns 60.0 ns 100.0 ns 140.0 ns
4 40.0 ns 120.0 ns 200.0 ns 280.0 ns
8 80.0 ns 240.0 ns 400.0 ns 560.0 ns
16 160.0 ns 480.0 ns 800.0 ns 1.1 µs
32 320.0 ns 960.0 ns 1.6 µs 2.2 µs
64 640.0 ns 1.9 µs 3.2 µs 4.5 µs
128 1.3 µs 3.8 µs 6.4 µs 9.0 µs
256 2.6 µs 7.7 µs 12.8 µs 17.9 µs
512 5.1 µs 15.4 µs 25.6 µs 35.8 µs
1024 10.2 µs 30.7 µs 51.2 µs 71.7 µs
2048 20.5 µs 61.4 µs 102.4 µs 143.4 µs
4096 41.0 µs 122.9 µs 204.8 µs 286.7 µs
8192 81.9 µs 245.8 µs 409.6 µs 573.4 µs
16384 163.8 µs 491.5 µs 819.2 µs 1.1 ms
32768 327.7 µs 983.0

s 1.6 ms 2.3 ms
65536 655.4 µs 2.0 ms 3.3 ms 4.6 ms