Consider a situation where an analog signal is driven by multiple digital drivers that take different nominal conditions from one or more power domains, such as the example shown below. Modules dig_A and dig_B belong to power domains PD1 and PD2, both of which are switchable power domains with a nominal condition of 1.2V and 2.5V. When the two modules drive the same port of an analog block ana_C, it is the case of multiple digital drivers in AMS-CPF.
When multiple digital drivers carrying CPF information drive a single analog port, the following describes how the multiple digital drivers are resolved:
- If all of these drivers belong to the same power domain: Continue the simulation without any warnings.
- If there is one or more power domains in power on or standby state: Report a warning, select the maximum nominal on or standby voltage, and apply it on the analog side.
- If there is one or more power domains in power off state: Report a warning, select the maximum nominal off voltage as the
vpso, and apply it on the analog side.
- If there is one or more power domains in power transition state: Report a warning and apply a random voltage on the analog side.
Here is an example of a warning message:
AMSCPF_VPI WARNING (at simtime 900.000000ns) : Multiple digital drivers are not allowed with a power smart connect module (top.connect__L2E_LPS__ddiscrete_2_4.Din), only one will be used:
PowerDomain : PD_Dig1 - Voltage : 1.800000 (selected)PowerDomain : PD_Dig2 - Voltage : 1.600000