EMDB6812 Datasheet, PDF (12/19 Pages) EM Microelectronic - MARIN SA – The EMDB6812 is based on two PCBs

R
EMDB6812
• PowerDown, Powers down the Host (eg. if battery level too low)
• GetTime, Read the Time from the RTC
• SetTime, Set the RTC
• SetTimer, Set a Timer. As soon as it reaches zero, the Host is powered up.
• SetPWM (eg. PWM Outputs, can be used eg. for Led backlight)
• SetOutput, Set the Aux outputs
• GetKeys, Get the Key States
• GetEOL, get the Battery Level
As soon as the Microcontroller detects that a key has been pressed, it sends the new key-State
automatically to the Host!
4.4 SOFTWARE
The Microprocessor has a Software-Half-Duplex UART incorporated which runs at 2400bps with 1
start-bit, 8 databits and 1 stopbit.
Via this UART the following commands can be executed:
• PowerDown
• GetTime
• SetTime
• SetTimer
• SetPWM (eg. For Led backlight)
• SetOutput
• GetKeys
• GetEOL
4.4.1 CPU operation Modes
The 32kHz Oscillator is always on for keeping accurate RTC timing
The CPU clock is switched off during Idle mode
During UART Reception/Transmission the Microcontroller uses the RC Oscillator, which
runs at approximately 1MHz
4.4.2 Main loop
PowerOn Reset
Init
Enable Host
no
RX on UART?
Send echo
Valid command?
no
Execute Cmd-Routine
Copyright © 2004, EM Microelectronic-Marin SA
12
www.emmicroelectronic.com