MMC2107 - Freescale Semiconductor

Freescale Semiconductor, Inc.
Serial Peripheral Interface Module (SPI)
Memory Map and Registers
17.7.8 SPI Port Data Direction Register
Address: 0x00cb_0008
Bit 7 6 5 4 3 2 1 Bit 0
Read:
Write:
RSVD7 RSVD6 RSVD5 RSVD4 DDRSP3 DDRSP2 DDRSP1 DDRSP0
Reset: 0 0 0 0 0 0 0 0
nc...
Freescale Semiconductor, I
NOTE:
Pin function: SS SCK
Read: Anytime
Write: Anytime
MOSI/
MOMI
Figure 17-9. SPI Port Data Direction Register (SPIDDR)
MISO/
SISO
RSVD[7:4] — Reserved
Writing to these read/write bits updates their values but has no effect
on functionality.
DDRSP[3:0] — Data Direction Bits
The DDRSP[3:0] bits control the data direction of SPIPORT pins.
Reset clears DDRSP[3:0].
1 = Corresponding pin configured as output
0 = Corresponding pin configured as input
In slave mode, DDRSP3 has no meaning or effect. In master mode,
DDRSP3 determines whether SPI port pin 3 is a mode-fault input, a
general-purpose output, or a slave-select output.
When the SPI is enabled (SPE = 1), the MISO, MOSI, and SCK pins:
• Are inputs if their SPI functions are input functions regardless of
the state of their DDRSP bits.
• Are outputs if their SPI functions are output functions only if their
DDRSP bits are set.
MMC2107 – Rev. 2.0
Technical Data
MOTOROLA Serial Peripheral Interface Module (SPI) 385
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