Datasheet

142
7728G–AVR–06/10
ATtiny87/ATtiny167
When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overrid-
den according to Table 13-1. For more details on automatic port overrides, refer to “Alternate
Port Functions” on page 72.
Note: 1. See “Alternate Functions of Port B” on page 81 for a detailed description of how to define the
direction of the user defined SPI pins.
The following code examples show how to initialize the SPI as a Master and how to perform a
simple transmission.
DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling
the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the actual data direc-
tion bits for these pins. E.g. if MOSI is placed on pin PB2, replace DD_MOSI with DDB2 and
DDR_SPI with DDRB.
Table 13-1. SPI Pin Overrides
(1)
Pin Direction, Master SPI Direction, Slave SPI
MOSI User Defined Input
MISO Input User Defined
SCK User Defined Input
SS User Defined Input