16-24 Intel® PXA255 Processor Developer’s Manual
Network SSP Serial Port
16.5.4 SSP Time Out Register (SSTO)
The SSTO register, shown in Table16-6,specifies the time-out value used to signal a period of
inactivity within the receive FIFO.
This is a read/write registers. Ignore reads from re served bits. Write zeros to reserved bits.
16.5.5 SSP Interrupt Test Register (SSITR)
SSITR, shown in Table16-7 on page16-25, cont ains bit fields used fo r testing purposes only.
Setting bits in this register causes the SSP controller to generate interrupts and DMA requests if
enabled. This is useful in testing the port’s functio nality.
1:0 SCMODE
SERIAL BIT-RATE CLOCK MODE:
Selects one of four serial clock modes when the PSP is selected (SSCR0[FRF]=0b11).
Its operation is similar to how SSCR1[SPO] and SSCR1[SPH] together determine the idle state
of SSPSCLK and on which edges data is driven and sampled.
0b00 - Data Driven (Falling), Data Sampled (Rising), Idle State (Low)
0b01 - Data Driven (Rising), Data Sampled (Falling), Idle State (Low)
0b10 - Data Driven (Rising), Data Sampled (Falling), Idle State (High)
0b11- Data Driven (Falling), Data Sampled (Rising), Idle State (High)
Table 16-5. SSPSP Bit Definitions (Sheet 2 of 2)
0x4140_002C SSPSP Network SSP Serial Port
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
reserved
DMYSTOP
reserved
SFRMWDTH SFRMDLY
DMYSTRT
STRTDLY
ETDS
SFRMP
SCMODE
Reset ? ? ? ? ? ? ? 0 0 ? 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bits Name Description
Table 16-6. SSTO Bit Definitions
0X4140_0028 SSTO Network SSP Serial Port
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
reserved TIMEOUT
Reset ? ? ? ? ? ? ? ? 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bits Name Description
31:24 — reserved
23:0 TIMEOUT
TIMEOUT:
Value used to set the time-out interval. When the TIMEOUT value is cleared, no time-out occurs
and SSSR[TINT] is not set.
The time-out interval is given by the equation: Time-out Interval = (TIMEOUT) / Peripheral Clock
Frequency