EVK-R41Z - User guide
UBX-19033357 - R03
Hardware description
Page 14 of 23
Figure 13: Schematic: User buttons
2.4.6
SPI flash
To assist development of applications requiring external storage, a 4 Mbit flash module is
provided (Adesto Tech. AT45DB041E-MHN2B-T). The flash uses an SPI interface with signals
shared with the expansion headers. When using multiple Chip Select (CS) signals, this allows
the same SPI bus to be used with both the Flash module and one or more SPI devices on an
expansion shield. However, some signals are also shared with the TSI user buttons.
Signal
R41Z I/O
SPI CLK
PTC16 (SW5)
SPI MOSI
PTC17
SPI MISO
PTC18
Flash CS_n
PTC19 (SW2)
Table 6: SPI flash port signals
Figure 14: Schematic: SPI flash
2.4.7
I2C acceleration/magnetometer sensor
For development of applications that require orientation and movement tracking, a combined
accelerometer and magnetometer is provided (NXP FXOS8700CQR1). The sensor can support
either SPI or I2C interfaces but is used exclusively with the I2C interface on the R41Z
evaluation board. When in I2C mode, the address of the sensor can be set using external pull-
up and pull-down resistors. The signals used for the I2C bus are shared with the expansion
headers. Because of the addressed nature of I2C it is possible to use this same bus to connect
to additional devices on a shield.