Nuvoton ISD91200 Series, Technical Reference Manual

Page: 253 / 473

ISD91200 Series Technical Reference Manual
Release Date: Sep 16, 2019
- 253 - Revision 2.4
Figure 5-55 Two Transactions in One Transfer (Burst Mode)
5.10.4.9 LSB First
The SPI1_CTL.LSB bit defines the bit order of data transmission. If LSB=0 then MSB of transfer word
is sent first in time. If LSB=1 then LSB of transfer word is sent first in time.
5.10.4.10 Transmit Edge
The SPI1_CTL.TXNEG bit determines whether transmit data is changed on the positive or negative
edge of the SPI1_SCLK serial clock. If TXNEG=0 then transmitted data will change state on the rising
edge of SPI1_SCLK. If TXNEG=1 then transmitted data will change state on the falling edge of
SPI1_SCLK.
5.10.4.11 Receive Edge
The SPI_CTL.RXNEG bit determines whether data is received at either the negative edge or positive
edge of serial clock SPI1_SCLK. If RXNEG=1 then data is clocked in on the falling edge of SPI1_SCLK.
If RXNEG=0 data is clocked in on the rising edge of SPI1_SCLK. Note that RXNEG should be the
inverse of TXNEG for standard SPI operation.
5.10.4.12 Word Sleep Suspend
The bit field SPI1_CTL.SLEEP provides a configurable suspend interval of SLEEP+2 serial clock
periods between successive word transfers in master mode. The suspend interval is from the last falling
clock edge of the preceding transfer word to the first rising clock edge of the following transfer word if
CLKP = 0. If CLKP = 1, the interval is from the rising clock edge of the preceding transfer word to the
falling clock edge of the following transfer word. The default value of SLEEP is 0x0 (2 serial clock
cycles). Word Sleep only occurs when TXNUM=1. For TXNUM=0, this parameter will determine a Byte
Sleep condition if the BYTESLEEP bit is set.
SPICLK
MOSI
MISO Tx0[30] Tx0[0] Tx1[31] Tx1[30]
LSB
Tx1[0]
MSB
Tx0[31]
Rx0[30] Rx0[0] Rx1[31] Rx1[30]
LSB
Rx1[0]
MSB
Rx0[31]
CLKP=0
CLKP=1
Word
Sleep
1st Transfer Word
2nd Transfer Word
Figure 5-56 Word Sleep Suspend Mode
SPICLK
MOSI
MISO Tx 0 [ 30 ] Tx 0 [ 0 ] Tx 1 [ 31 ] Tx 1 [ 30 ]
LSB
Tx 1 [ 0 ]
MS
Tx 0 [ 31 ]
Rx 0 [ 30 ] Rx 0 [ 0 ] Rx 1 [ 31 ] Rx 1 [ 30 ]
LSB
Rx 1 [ 0 ]
MS
Rx 0 [ 31 ]
CLK = 0
CLK = 1
Word suspend
1st Transaction Word
2
nd Transaction Word