AT83EC5123 ATMEL Corporation, AT83EC5123 Datasheet - Page 143

• Manufacturer Part Number: AT83EC5123
• Description: (AT8xx512x) Smart Card Reader ICs
• Manufacturer: ATMEL Corporation

Figure 86. Power-down Exit Waveform
Table 107. State of Ports
Note:
Reduced EMI Mode
4202B–SCR–07/03
Power-down
Power-down
Mode
Idle
Idle
1. Port 0 can force a 0 level. A "one" will leave port floating.
Program Memory
External
External
Internal
Internal
XTAL1
INT0
INT1
Exit from power-down by reset redefines all the SFRs, exit from power-down by external
interrupt does no affect the SFRs.
Exit from power-down by either reset or external interrupt does not affect the internal
RAM content.
Note:
Table 107 shows the state of ports during idle and power-down modes.
The ALE signal is used to demultiplex address and data buses on port 0 when used with
external program or data memory. Nevertheless, during internal code execution, ALE
signal is still generated. In order to reduce EMI, ALE signal can be disabled by setting
AO bit.
The AO bit is located in AUXR register at bit location 0. As soon as AO is set, ALE is no
longer output but remains active during MOVX and MOVC instructions and external
fetches. During ALE disabling, ALE pin is weakly pulled high.
ALE
Active phase
1
1
0
0
If idle mode is activated with power-down mode (IDL and PD bits set), the exit sequence
is unchanged, when execution is vectored to interrupt, PD and IDL bits are cleared and
idle mode is not entered.
PSEN
1
1
0
0
Port Data
Power-down phase
Port Dat*
PORT0
Floating
Floating
(1)
Port Data
Port Data
Port Data
Port Data
PORT1
Oscillator restart phase
Port Data
Port Data
Port Data
PORT2
Address
AT8xC5122/23
Port Data
Port Data
Port Data
Port Data
PORT3
Active phase
Port Data
Port Data
Port Data
Port Data
PORTI2
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