Datasheet

Serial Peripheral Interface (SPI)
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
206 Freescale Semiconductor
The generic names of the SPI I/O registers are:
• SPI control register (SPCR)
• SPI status and control register (SPSCR)
• SPI data register (SPDR)
Table 19-2 shows the names and the addresses of the SPI I/O registers.
19.4 Functional Description
Figure 19-1 summarizes the SPI I/O registers and Figure 19-2 shows the structure of the SPI module.
The SPI module allows full-duplex, synchronous, serial communication between the MCU and peripheral
devices, including other MCUs. Software can poll the SPI status flags or SPI operation can be interrupt
driven. All SPI interrupts can be serviced by the CPU.
The following paragraphs describe the operation of the SPI module.
Table 19-2. I/O Register Addresses
Register Name Address
SPI Control Register (SPCR) $0010
SPI Status and Control Register (SPSCR) $0011
SPI Data Register (SPDR) $0012
AddrRegister NameR/WBit 7654321Bit 0
$0010
SPI Control Register
(SPCR)
Read:
SPRIE R SPMSTR CPOL CPHA SPWOM SPE SPTIE
Write:
Reset:00101000
$0011
SPI Status and Control Register
(SPSCR)
Read: SPRF
ERRIE
OVRF MODF SPTE
MODFEN SPR1 SPR0
Write:
Reset:00001000
$0012
SPI Data Register
(SPDR)
Read:R7R6R5R4R3R2R1R0
Write: T7 T6 T5 T4 T3 T2 T1 T0
Reset: Unaffected by Reset
R
= Reserved
= Unimplemented
Figure 19-1. SPI I/O Register Summary