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 an d RxFIFO. The bit position assignments for this register are

shown in the following register display. The settings for this register are described in Table13-5.

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 ra te clock (SPICLK1) or the

CLK32 signal. Unless a different crystal is used, the CLK32 signal is 32.768kHz. The bit position

assignments for this register are shown in the following register display. The settings for this register are

described in Table13-6 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 fiel d 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 CounterThis 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.