C8051T620/1/6/7 & C8051T320/1/2/3
64
Rev. 1.2
11.2. Voltage Regulator (REG1)
Under default conditions, the internal REG1 regulator will remain on when the device enters STOP mode.
This allows any enabled reset source to generate a reset for the device and bring the device out of STOP
mode. For additional power savings, the STOPCF bit can be used to shut down the regulator and the inter-
nal power network of the device when the part enters STOP mode. When STOPCF is set to 1, the RST pin
and a full power cycle of the device are the only methods of generating a reset.
REG1 offers an additional low power mode intended for use when the device is in suspend mode. This low
power mode should not be used during normal operation or if the REG0 Voltage Regulator is disabled. See
Table 7.5 for normal and low power mode supply current specifications. The REG1 mode selection is con-
trolled via the REG1MD bit in register REG01CN.
Important Note:
At least 12 clock instructions must occur after placing REG1 in low power mode before
the Internal High Frequency Oscillator is Suspended (OSCICN.5 = 1b).