23. Serial Peripheral Interface (HSPI)
Rev.1.00 Jan. 10, 2008 Page 1167 of 1658
REJ09B0261-0100
23.4.3 Timing Diagrams
The following diagrams explain the timing relationship of all shift and sample processes in the
HSPI. Figure 23.3 shows the conditions when FBS = 0, figure 23.4 shows the conditions when
FBS = 0 (continuous transfer), figure 23.5 shows the conditions when FBS = 1, and figure 23.6
shows the conditions when FBS = 1 (continuous transfer). It can be seen that if CLKP in SPCR is
0, transmit data is shifted at the falling edge of HSPI_CLK and receive data is sampled at the
rising edge of HSPI_CLK. The opposite is true when CLKP = 1.
Data transfer cycle
HSPI_CLK (CLKP = 0)
HSPI_CLK (CLKP = 1)
1 432 8765
HSPI_TX MSB 6 5 4 3 2 1 LSB
MSB 6 5 4 3 2 1 LSB *HSPI_RX
HSPI_CS
Figure 23.3 Timing Conditions when FBS = 0
HSPI_CLK (CLKP = 0)
HSPI_CLK (CLKP = 1)
1 8..2 9 16..10
HSPI_TX MSB 6 LSB MSB 6 LSB
MSB 6 LSB MSB 6 LSB *
HSPI_RX
HSPI_CS
Data transfer cycle
*
Figure 23.4 Timing Conditions when FBS = 0 (Continuous Transfer)