Rohm RKX-EVK-001, User Manual

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© 2022 ROHM Co., Ltd. No. 64UG118E Rev.002
Feb.2022
User’s Guide
Multiple Bits Function
Some bits are grouped together if they make up one setting and have a predefined function for each combination of bits. For example, the Full-
Scale range of the KX132-1211 accelerometer is defined by the value of GSEL1 and GSEL0 bits. These two bits are grouped together in the
register editor as GSEL and the user can select the actual function, instead of modifying the individual bits. When selection is made, click on the
Write button to write the setting to the device.
Reserved Bits
If the bit is grayed out, it means it is reserved and thus the register editor does not provide a way to modify it to avoid unexpected behavior. For
example, bit 1 in CNTL1 register is reserved ( Figure 53 ).
Figure 53. CNTL1 register of KX132-1211
Writing to an 8-bit register
Certain functions of the device can span across the entire 8-bit register and their value is between 0 and 255 ( Figure 54 ). Other functions can take
less than the full 8-bit register. For example, the FTDH value is a 5-bit value and is between 0-31 ( Figure 55) . In order to change the value, the user
can simply enter the value either as a decimal or as a hex value (the hex format is 0xFF) and press the Enter key. Once the value is written, the
“value” field of the register gets updated with the new value. It is possible to read the value back. Also, if the “Events view panel” function is enabled
in the View menu ( 1.3.8.2 Events view panel) the write information will be shown in the events window.
Figure 54. WUFC 8-bit value (0-255)
Figure 55. FTDH 5-bit value (0-31)
Changing device settings that spans over two registers
Some functions of the device may span more than 8-bits and are thus split between 2 or more registers. For example, the WUFTH function of the
KX132-1211 is an 11-bit value (0 to 2047). The lower 8 bits are stored in the WUFTH register (0x49), and the upper 3 bits in the BTSWUFTH
register (0x4A) ( Figure 56) .
Figure 56. WUFTH 11-bit value (0-2047) spanned across two registers
To simplify the register update, the user can write the entire value to the lowest byte register (e.g., a value from 0 to 2047 to WUFTH_L register),
and the register editor will update both registers accordingly. For example, to set the WUFTH value to 950 (0x03B6), write 950 to the WUFTH
register 0x49, and the register WUFTH (0x49) will store the value 0xB6, while the register BTSWUFTH (0x4A) will store the value 0x03.