MC68VZ328 Integrated Processor User's Manual
13-10 MC68VZ328 User’s Manual
SPI 1 Programming Model
13.3.5 SPI 1 Test Register
The configurable SPI test (SPITEST) register indicates the state machine status of SPI 1 as well as the
number of words currently in the TxFIFO and RxFIFO. The bit position assignments for this register are
shown in the following register display. The settings for this register are described in Table 13-5.
SPITEST SPI 1 Test Register 0x(FF)FFF708
13.3.6 SPI 1 Sample Period Control Register
This register controls the time inserted between data transactions in master mode. The time inserted
between samples can be from 0 to about 1 second at the resolution of the data rate clock (SPICLK1) or the
CLK32 signal. Unless a different crystal is used, the CLK32 signal is 32.768 kHz. The bit position
assignments for this register are shown in the following register display. The settings for this register are
described in Table 13-6 on page 13-11.
BIT
15
1413121110987654321
BIT
0
SSTATUS RXCNT TXCNT
TYPE
rw rw rw rw rw rw rw rw rw rw rw rw
RESET
0000000000000000
0x0000
Table 13-5. SPI 1 Test Register Description
Name Description Setting
Reserved
Bits 15–12
Reserved These bits are reserved and
should be set to 0.
SSTATUS
Bits 11–8
State Machine Status—This field indicates the state
machine status. These bits are used for test purposes only.
See description.
RXCNT
Bits 7–4
RxFIFO Counter—This field indicates the number of data
words in the RxFIFO.
0000 = RXFIFO is empty.
0001 = 1 data word in RXFIFO.
0010 = 2 data words in RXFIFO.
0011 = 3 data words in RXFIFO.
0100 = 4 data words in RXFIFO.
0101 = 5 data words in RXFIFO.
0110 = 6 data words in RXFIFO.
0111 = 7 data words in RXFIFO.
1000 = 8 data words in RXFIFO.
TXCNT
Bits 3–0
TxFIFO Counter—This field indicates the number of data
words in the TxFIFO.
0000 = TxFIFO is empty.
0001 = 1 data word in TxFIFO.
0010 = 2 data words in TxFIFO.
0011 = 3 data words in TxFIFO.
0100 = 4 data words in TxFIFO.
0101 = 5 data words in TxFIFO.
0110 = 6 data words in TxFIFO.
0111 = 7 data words in TxFIFO.
1000 = 8 data words in TxFIFO.