ADLINK Technology cExpress-AL - Board Specific SEMA Functions

40 Smart Embedded Management Agent (SEMA)
5.1. Board Specific SEMA Functions
5.1.1. Voltages
The BMC of the cExpress-AL implements a voltage monitor and samples several onboard voltages. The voltages
can be read by calling the SEMA function “Get Voltages”. The function returns a 16-bit value divided into high-byte
(MSB) and low-byte (LSB).
ADC Channel Voltage Name Voltage Formula [V]
0 VCC_CORE (MSB<<8 + LSB) x 3.3 / 1024
1 VGFX (MSB<<8 + LSB) x 3.3 / 1024
2 VMEM (MSB<<8 + LSB) x 3.3 / 1024
3 5VSB (MSB<<8 + LSB) x 1.8 x 3.3 / 1024
4 VIN (12V) (MSB<<8 + LSB) x 6 x 3.3 / 1024
5 5V (MSB<<8 + LSB) x 1.8 x 3.3 / 1024
6 3.3V (MSB<<8 + LSB) x 1.1 x 3.3 / 1024
7 3.3VSB (MSB<<8 + LSB) x 1.1 x 3.3 / 1024
8 RTC
(build option support)
(MSB<<8 + LSB) x 3.3 / 1024
Table 7: SEMA Onboard Voltage Monitor
5.1.2. Main Current
The BMC of the cExpress-AL implements a current monitor. The current can be read by calling the SEMA function
“Get Main Current”. The function returns four 16-bit values divided in high-byte (MSB) and low-byte (LSB). These 4
values represent the last 4 currents drawn by the board. The values are sampled every 250ms. The order of the 4
values is NOT in chronological order. Access by the BMC may increase the drawn current of the whole system. In
this case, there are still 3 samples not influenced by the read access.
Main Current = (MSB_n<<8 + LSB_n) x 8.06mA
5.1.3. BMC Status
This register shows the status of BMC controlled signals on the cExpress-AL.
Status Bit Signal
0 WDT_OUT
1 LVDS_VDDEN
2 LVDS_BKLTEN
3 BIOS_MODE
4 POSTWDT_DISn
5 SEL_BIOS
6 BIOS_DIS0n
7 BIOS_DIS1n
Table 8: SEMA BMC Status