Data Sheet

Bluegiga – A Silicon Labs Company 28
9.2 Connecting an external device using SPI interface
Bluegiga Bluetooth Smart Ready module BT121 contains two physical SPI peripherals (SPI 1 and SPI2) each
with alternative configurations (Alt 1 and Alt 2). All of the four optional configurations can be used to connect
different types of peripheral devices to the module. Pin configurations for the four SPI interface options are
listed in Table 2. An example of this type of interfacing is shown in Figure 19 below. In the example below a
generic EEPROM memory peripheral chip is connected to the BT121 using the SPI 1 Alt 2 option.
Figure 19 Connecting an external device with BT121 using SPI interface