mc13109 Freescale Semiconductor, Inc, mc13109 Datasheet - Page 20

• Manufacturer Part Number: mc13109
• Description: Universal Cordless Telephone Subsystem
• Manufacturer: Freescale Semiconductor, Inc

Inactive Mode Operation and Hardware Interrupt
down all circuitry including the microprocessor (MPU). First
put the MC13109 into the Inactive mode, which turns off the
MPU Clock Output (see Figure 22), and then disable the
microprocessor. In order to give the MPU adequate time to
power down, the MPU Clock output remains active for a
minimum of one reference counter cycle (about 200 s) after
the command is given to switch into the “Inactive” mode. An
external timing circuit should be used to initiate the turn–on
sequence. The “CD Out” pin has a dual function. In the Active
and R x modes it performs the carrier detect function. In the
NOTE: 1. In Standby and Inactive Modes, “PLL V ref ” remains powered but is not regulated. It will fluctuate with V CC .
“PLL V ref ” Regulated
Voltage
MPU Interface
2nd LO Oscillator
MPU Clock Output
RF Receiver
1st LO VCO
R x PLL
Carrier Detect
Data Amp
Low Battery Detect
T x PLL
R x Audio Path
T x Audio Path
20
In some handset applications it may be desirable to power
Delay after MPU selects Inactive Mode to when CD turns off.
CD Out/Hardware Interrupt
MPU Clock Out
Circuit Blocks
Mode
EN
Figure 21. Circuit Blocks Powered During Power Saving Modes
Active/R x
CD Out Low
Figure 22. Hardware Interrupt Operation
MC13109
MPU Initiates
Inactive Mode
CD Turns Off
Active
X
X
X
X
X
X
X
X
X
X
X
X
X
Inactive
Standby and Inactive modes the carrier detect circuit is
disabled and the “CD Out” pin is in a “High” state due to the
external pull–up resistor. In the Inactive mode the “CD Out”
pin is the input for the hardware interrupt function. When the
“CD Out” pin is pulled “low” by the external timing circuit, the
MC13109 swtiches from the Inactive to the Interrupt mode
thereby turning on the MPU Clock Output. The MPU can then
resume control of the combo IC. The “CD Out” pin must
remain low until the MPU changes the operating mode from
Interrupt to Standby, Active or R x modes.
“MPU Clock Out” remains active for a minimum of one count of reference
counter after “CD Out/Hardware Interrupt” pin goes high
R x
X
X
X
X
X
X
X
X
X
X
External Timer
Pulls Pin Low
Interrupt
MOTOROLA ANALOG IC DEVICE DATA
Standby
X 1
X
X
X
Standby/R x /Active
MPU Initiates
Mode Change
Timer Output
Disabled
Inactive
X 1
X