參數(shù)資料
型號(hào): A8351601L-40
廠商: AMIC Technology Corporation
英文描述: 5015 RR 4#8 SKT RECP
中文描述: 條碼閱讀器
文件頁數(shù): 34/44頁
文件大?。?/td> 439K
代理商: A8351601L-40
A8351601 Series
(July, 2002, Version 1.0)
33
AMIC Technology, Inc.
Power-Saving Modes of Operation
The A8351601 has two power-reducing modes. Idle and
Power-down. The input through which backup power is
supplied during these operations is VCC. Figure 17 shows
the internal circuitry which implements these features. In
the Idle mode (IDL = 1), the oscillator continues to run and
the Interrupt, Serial Port, and Timer blocks continue to be
clocked, but the clock signal is gated off to the CPU. In
Power-down (PD = 1), the oscillator is frozen. The Idle and
Power-down modes are activated by setting bits in Special
Function Register PCON.
Idle Mode
An instruction that sets PCON.0 is the last instruction
executed before the Idle mode begins. In the Idle mode,
the internal clock signal is gated off to the CPU, but not to
the Interrupt, Timer, and Serial Port functions. The CPU
status is preserved in its entirety: the Stack Pointer,
Program Counter, Program Status Word, Accumulator, and
all other registers maintain their data during Idle. The port
pins hold the logical states they had at the time Idle was
activated. ALE and
PSEN
hold at logic high levels.
There are two ways to terminate the Idle. Activation of any
enabled interrupt will cause PCON.0 to be cleared by
hardware, terminating the Idle mode. The interrupt will be
serviced, and following RETI the next instruction to be
executed will be the one following the instruction that put
the device into Idle.
The flag bits GF0 and GF1 can be used to indicate whether
an interrupt occurred during normal operation or during an
Idle. For example, an instruction that activates Idle can
also set one or both flag bits. When Idle is terminated by
an interrupt, the interrupt service routine can examine the
flag bits.
The other way of terminating the Idle mode is with a
hardware reset. Since the clock oscillator is still running,
the hardware reset must be held active for only two
machine cycles (24 oscillator periods) to complete the
reset.
The signal at the RST pin clears the IDL bit directly and
asynchronously. At this time, the CPU resumes program
execution from where it left off; that is, at the instruction
following the one that invoked the Idle Mode. As shown in
Figure 16, two or three machine cycles of program
execution may take place before the internal reset
algorithm takes control. On-chip hardware inhibits access
to the internal RAM during his time, but access to the port
pins is not inhibited. To eliminate the possibility of
unexpected outputs at the port pins, the instruction
following the one that invokes Idle should not write to a port
pin or to external data RAM.
Power-down Mode
An instruction that sets PCON.1 is the last instruction
executed before Power-down mode begins. In the Power
down mode, the on-chip oscillator stops. With the clock
frozen, all functions are stopped, but the on-chip RAM and
Special function Registers are held. The port pins output
the values held by their respective SFRs. ALE and
PSEN
output high.
In the Power-down mode of operation, VCC can be
reduced to as low as 2V. However, VCC must not be
reduced before the Power-down mode is invoked, and
VCC must be restored to its normal operating level before
the Power-down mode is terminated. The reset that
terminates Power-down also frees the oscillator. The reset
should not be activated before VCC is restored to its
normal operating level and must be held active long
enough to allow the oscillator to restart and stabilize
(normally less than 10 msec).
Reset redefines all the SFRs but does not change the on-
chip RAM.
OSC
XTAL2
CLOCK
GEN
IDL
PD
CPU
INTERRUPT,
SERIAL PORT,
TIMER BLOCKS
XTAL1
Figure 17. Idle and Power-Down Hardware
相關(guān)PDF資料
PDF描述
A8351601 Bar Code Reader
A8351601-40 Bar Code Reader
A8423 LIN Bus Transceiver with Integrated Voltage Regulator
A8423KL LIN Bus Transceiver with Integrated Voltage Regulator
A8430 White LED Driver Constant Current Step-up Converter
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
A8351601SERIES 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Bar Code Reader
A83516-12 制造商:AMICC 制造商全稱:AMIC Technology 功能描述:8 Bit Microcontroller
A83516-24 制造商:AMICC 制造商全稱:AMIC Technology 功能描述:8 Bit Microcontroller
A83516-40 制造商:AMICC 制造商全稱:AMIC Technology 功能描述:8 Bit Microcontroller
A83516L-12 制造商:AMICC 制造商全稱:AMIC Technology 功能描述:8 Bit Microcontroller