JAJSKM1C october 2019 – september 2021 UCC5870-Q1
PRODUCTION DATA
The Daisy Chain configuration is shown in Figure 7-40. In this configuration, the MCU MOSI connects to the SDI of the first device and the MISO connects to the SDO of the last device. The SDO of each of the device connects to the SDI of the next device in the system (excluding the last device). The system effectively becomes a communication shift register. During communication, the host continuously clocks in data for all the devices in the system while holding the nCS pin low. While the nCS input is low, the SDO shifts data out as the data is clocked into the SDI shift register as shown in Figure 7-41. Once nCS is pulled high, the 16-bits in the SDI register are latched and acted upon by the device. This configuration drastically reduces the number of GPIOs required, but it does not allow random access to the devices.