FlashFlex51 MCU
SST89E52RD2 / SST89E54RD2 / SST89E58RD2 / SST89E516RD2
SST89V52RD2 / SST89V54RD2 / SST89V58RD2 / SST89V516RD2
Preliminary Specifications
SPI Control Register (SPCR)
Location
7
6
5
4
3
2
1
0
Reset Value
D5H
SPIE
SPE
DORD
MSTR
CPOL
CPHA
SPR1
SPR0
00H
Symbol
SPIE
Function
If both SPIE and ES are set to one, SPI interrupts are enabled.
SPE
SPI enable bit.
0: Disables SPI.
1: Enables SPI and connects SS#, MOSI, MISO, and SCK to pins P1.4, P1.5, P1.6, P1.7.
DORD
MSTR
CPOL
CPHA
Data Transmission Order.
0: MSB first in data transmission.
1: LSB first in data transmission.
Master/Slave select.
0: Selects Slave mode.
1: Selects Master mode.
Clock Polarity
0: SCK is low when idle (Active High).
1: SCK is high when idle (Active Low).
Clock Phase control bit.
0: Shift triggered on the leading edge of the clock.
1: Shift triggered on the trailing edge of the clock.
SPR1, SPR0 SPI Clock Rate Select bits. These two bits control the SCK rate of the device
configured as master. SPR1 and SPR0 have no effect on the slave. The relationship
between SCK and the oscillator frequency, fOSC, is as follows:
SPR1
SPR0
SCK = fOSC divided by
0
0
1
1
0
1
0
1
4
16
64
128
SPI Status Register (SPSR)
Location
7
6
5
4
3
2
1
0
Reset Value
AAH
SPIF
WCOL
-
-
-
-
-
-
00xxxxxxb
Symbol
Function
SPI Interrupt Flag.
SPIF
Upon completion of data transfer, this bit is set to 1.
If SPIE =1 and ES =1, an interrupt is then generated.
This bit is cleared by software.
WCOL
Write Collision Flag.
Set if the SPI data register is written to during data transfer.
This bit is cleared by software.
©2004 Silicon Storage Technology, Inc.
S71255-00-000
3/04
30
SST [ SILICON STORAGE TECHNOLOGY, INC ]
