Data Sheet

UM7 DATASHEET
Rev. 1.6 – Released 1/10/2016
17
Commands are initiated over the SPI bus by sending a write operation to the command
address, with all four data bytes at zero. The UM7 will not report that a command was executed
over the SPI bus except for during a GET_FW_REVISION command, which causes the firmware
revision to be sent over the MISO line during the next four byte transfers on the bus.
For example, to execute a zero rate gyros command over the SPI bus, the following data bytes
should be sent over the bus: 0x01 0xAC 0x00 0x00 0x00 0x00.
Similarly, to query the UM7 to get the firmware revision over the SPI bus, the following
sequence should be used: 0x01 0xAA 0x00 0x00 0x00 0x00. The UM7 will send the firmware
revision over the MISO line during the last four byte transfers.
Figure 1 - SPI Bus Timing
Table 1 - SPI Bus Timing
Name
Description
Min
Max
ss
t
Slave-select setup time
1 us
NA
clk
t
Clock period
0.1 us
NA
clk
f
Clock frequency
NA
10 Mhz
hold
t
Data hold time
10 ns
NA
setup
t
Data setup time
10 ns
NA
SCK
SS
MISO
MOSI
MSB OUT
MSB IN LSB IN
LSB OUT
ss
t
clk
t
hold
t
setup
t
SCK
SS
MISO
MOSI
MSB OUT
MSB IN LSB IN
LSB OUT
ss
t
clk
t
hold
t
setup
t