Sonic Alert msm85c154hvs Clock Radio User Manual


 
INTERNAL SPECIFICATIONS
169
4.9 CPU Power Down Mode (IDLE, PD, and HPD) Cancellation (CPU Activation)
4.9.1 Outline
CPU power down mode (IDLE, PD, and HPD) can be cancelled (CPU activation) in the
following two ways.
The CPU is reset when a “1” reset signal is applied to the CPU RESET pin, and the program
is executed from address 0. This method can be used in IDLE, PD, and HPD modes.
By generating the respective interrupt source signals, the program can be executed from the
interrupt address, and can also be continued from the next address after the stop address.
This method can be used in IDLE and PD modes.
4.9.2 Cancellation by CPU resetting (RESET pin)
The CPU is reset when a “1” level signal is applied (for at least 1µAsec.) to the CPU RESET
pin, and the CPU power down mode (IDLE, PD, or HPD) is cancelled. Programs are
subsequently executed by the CPU from address 0. The reset cancellation time charts are
outlined in Figures 4-69 thru 4-74.