User`s guide

LZ87010 Advance User’s Guide System Clocking
1/15/03 2-7
2.3.2 PCON (Power Control) Register
The PCON (Power Control) register selects the current power-saving mode (one of: Active,
Idle, and Stop), and implements a bit to double the baud rate of UART 0 (in Modes 1 - 3).
It also contains two general-purpose read/write bits that can be used by software for any
desired purpose.
Table 2-6. PCON (Power Control) Register
BIT 7 6 5 4 3 2 1 0
FIELD SMOD /// /// /// GF1 GF0 PD IDL
RESET 000 0 0 000
RW RW RO RO RO RW RW RW RW
ADDR 0x87
Table 2-7. PCON Register Fields
BIT NAME DESCRIPTION
7SMOD
Serial Clock Mode If ‘1’, the baud rate of UART 0 will double in modes 1, 2,
and 3. Otherwise, UART 0 runs at its nominal rate. This bit has no effect on
UART 1.
6:4 /// Reserved Reads return ‘0’; writes are ignored.
3:2 GF[1:0]
General-purpose Flag Bits These read/write bits do not affect the operation of
the device. They can be used by software for any desired purpose.
1PD
Power Down The device enters Stop mode when this bit is set to ‘1’. In Stop
mode, all circuitry is halted and power consumption is very low. Stop mode can
only be exited through a device Reset.
0IDL
Idle Mode The device enters Idle mode when this bit is set to ‘1’. In Idle mode,
the processor core halts, but the UARTs, timers, and external interrupt signals are
still active. Idle mode is exited automatically when an interrupt is received from an
active peripheral, or on a device Reset.