ST7FLITE29 STMICROELECTRONICS [STMicroelectronics], ST7FLITE29 Datasheet - Page 79

• Manufacturer Part Number: ST7FLITE29
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, TIMERS, SPI
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

SERIAL PERIPHERAL INTERFACE (Cont’d)
CONTROL/STATUS REGISTER (SPICSR)
Read/Write (some bits Read Only)
Reset Value: 0000 0000 (00h)
Bit 7 = SPIF Serial Peripheral Data Transfer Flag
0: Data transfer is in progress or the flag has been
1: Data transfer between the
Note: While the SPIF bit is set, all writes to the
SPIDR register are inhibited until the SPICSR reg-
ister is read.
Bit 6 = WCOL Write Collision status (Read only).
This bit is set by hardware when a write to the
SPIDR register is done during a transmit se-
quence. It is cleared by a software sequence (see
Figure
0: No write collision occurred
1: A write collision has been detected
Bit 5 = OVR S PI Overrun error (Read only).
This bit is set by hardware when the byte currently
being received in the shift register is ready to be
transferred into the SPIDR register while SPIF = 1
(See
SPIE = 1 in SPICSR register. The OVR bit is
cleared by software reading the SPICSR register.
0: No overrun error
1: Overrun error detected
Bit 4 = MODF Mode Fault flag (Read only).
This bit is set by hardware when the SS pin is
pulled low in master mode (see
Master Mode Fault
be generated if SPIE=1 in the SPICSR register.
This bit is cleared by a software sequence (An ac-
cess to the SPICSR register while MODF=1 fol-
lowed by a write to the SPICR register).
0: No master mode fault detected
1: A fault in master mode has been detected
Bit 3 = Reserved, must be kept cleared.
SPIF
cleared.
nal device has been completed.
(Read only).
This bit is set by hardware when a transfer has
been completed. An interrupt is generated if
SPIE=1 in the SPICR register. It is cleared by a
software sequence (an access to the SPICSR
register followed by a write or a read to the
SPIDR register).
7
Section
47).
WCOL
11.4.5.2). An interrupt is generated if
OVR
(MODF)). An SPI interrupt can
MODF
Device
-
Section 11.4.5.1
SOD
and an exter-
SSM
SSI
0
Bit 2 = SOD SPI Output Disable.
This bit is set and cleared by software. When set, it
disables the alternate function of the SPI output
(MOSI in master mode / MISO in slave mode)
0: SPI output enabled (if SPE=1)
1: SPI output disabled
Bit 1 = SSM SS Management.
This bit is set and cleared by software. When set, it
disables the alternate function of the SPI SS pin
and uses the SSI bit value instead. See
11.4.3.2 Slave Select
0: Hardware management (SS managed by exter-
1: Software management (internal SS signal con-
Bit 0 = SSI SS Internal Mode.
This bit is set and cleared by software. It acts as a
‘chip select’ by controlling the level of the SS slave
select signal when the SSM bit is set.
0 : Slave selected
1 : Slave deselected
DATA I/O REGISTER (SPIDR)
Read/Write
Reset Value: Undefined
The SPIDR register is used to transmit and receive
data on the serial bus. In a master device, a write
to this register will initiate transmission/reception
of another byte.
Notes: During the last clock cycle the SPIF bit is
set, a copy of the received data byte in the shift
register is moved to a buffer. When the user reads
the serial peripheral data I/O register, the buffer is
actually being read.
While the SPIF bit is set, all writes to the SPIDR
register are inhibited until the SPICSR register is
read.
Warning: A write to the SPIDR register places
data directly into the shift register for transmission.
A read to the SPIDR register returns the value lo-
cated in the buffer and not the content of the shift
register (see
D7
nal pin)
trolled by SSI bit. External SS pin free for gener-
al-purpose I/O)
7
D6
Figure
D5
42).
D4
Management.
D3
D2
ST7LITE2
D1
Section
79/131
D0
0
1