M-G362 Datasheet, PDF (42/69 Pages) Epson Company – IMU (Inertial Measurement Unit)

7. User Registers
A host device (for example, a microcontroller) can control the IMU by accessing the control registers
inside the device.
The registers are accessed in this device using a WINDOW method. The prescribed window number is
first written to WINDOW_ID of WIN_CTRL[0x7E(W0/W1)] bit [7:0], then the desired register address
can be accessed. The WIN_CTRL [0x7E(W0/W1)] register can always be accessed with out needing to
set the window number.
During the Power-On Start-Up Time or the Reset Recovery time specified in the Table 2.4 Interface
Specifications, all the register values are undefined because internal initialization is in progress. Ensure
the IMU registers are only accessed after the Power-On Start-Up Time is over.
For information about the initial values of the control registers after internal initialization is finished, see
the “Default” column in the Table 7.1. The control registers with ○ mark in the “Flash Backup” column
can be saved to the non-volatile memory by the user, and the initial values after the power on will be the
values read from the non-volatile memory. If the read out from the non-volatile memory fails, the
FLASH_ERR (DIAG_STAT [0x04(W0)] bit[2]) is set to 1 (error).
Please ensure that the IMU is in the Configuration Mode before writing to registers. In the Sampling
Mode, writing to registers is ignored except for the following cases.
• MODE_CTRL [0x02(W0)] bit [9:8] in MODE_CMD
• GPIO [0x08(W0)] bit [10:8] in GPIO_DATA
• GLOB_CMD [0x0A(W1)] bit 7 in SOFT_RST
• WIN_CTRL [0x7E(W0/W1)] bit [7:0] in WINDOW_ID
While in the UART Auto Mode and Sampling Mode is active, register read access is not supported.
Otherwise, the sampling data transmitted in the UART Auto Mode will be corrupted by the response
data from the register read.
Each register is 16-bit wide and one address is assigned to every 8 bits. Registers are read in 16-bit
words and are written in 8-bit words. The byte order of each 16-bit register is little endian, but the byte
order of the 16-bit data transferred over the digital interface is big endian
Table 7.1 shows the register map, and Section 7.1 through Section 7.18 describes the registers in detail.
The “-” sign in the register assignment table in Section 7.1 through Section 7.18 means “reserved”.
Write a “0” to reserved bits during a write operation.
During a read operation, a reserved bit can return either 0 or 1 (“don’t care”).
Writing to a read-only register is prohibited.
NOTE: The explanation of the register notation MODE_CTRL [0x02(W0)] bit [9:8] is as follows:
• MODE_CTRL:
• [0x02(W0)]:
• bit[9:8]:
Register name
First number is the Register Address, (W0) means Window Number “0”
Bits 9 to 8
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Seiko Epson Corporation
M-G362PDC1 Data Sheet
Rev.20131217