5. Device Identification
5.1 Device Identification
The SFR map includes registers that may be used to identify the device family (DEVICEID), derivative (DERIVID), and revision (RE-
VID). These SFRs can be read by firmware at runtime to determine the capabilities of the MCU that is executing code. This allows the
same firmware image to run on MCUs with different memory sizes and peripherals, and dynamically change functionality to suit the
capabilities of that MCU.
5.2 Unique Identifier
A128-bit universally unique identifier (UUID) is pre-programmed into all devices. The value assigned to a device is random and not
sequential, but it is guaranteed unique. The UUID resides in the read-only area of flash memory which cannot be erased or written in
the end application. The UUID can be read by firmware or through the debug interface at flash locations 0xFFC0-0xFFCF.
Table 5.1. UID Location in Memory
Device
Flash Addresses
EFM8UB30F40G
EFM8UB31F40G
EFM8UB32F40G
(MSB)
0xFFCF, 0xFFCE, 0xFFCD, 0xFFCC,
0xFFCB, 0xFFCA, 0xFFC9, 0xFFC8,
0xFFC7, 0xFFC6, 0xFFC5, 0xFFC4,
0xFFC3, 0xFFC2, 0xFFC1, 0xFFC0
(LSB)
5.3 Device Identification Registers
5.3.1 DEVICEID: Device Identification
Bit
7
6
5
4
3
2
1
0
Name
DEVICEID
Access
R
Reset
0x36
SFR Page = 0x0; SFR Address: 0xB5
Bit
Name
Reset
Access Description
7:0
DEVICEID
0x36
R
Device ID.
This read-only register returns the 8-bit device ID.
EFM8UB3 Reference Manual
Device Identification
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