AT83EC5123 ATMEL Corporation, AT83EC5123 Datasheet - Page 145

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

Smart Card Interface
Entering in Power-down Mode In order to reduce the power consumption, a power-down or idle mode can be invoked
Exiting from Power-down
Mode
Keyboard Interface
Entering in Power-down Mode In order to reduce the power consumption, the microcontroller can be set in power-down
Exiting from Power-down
Mode
4202B–SCR–07/03
by software (see Table 13, PCON register). Before activating these modes the applica-
tion will need to:
Power-off the Smart Card Interface by applying the following sequence:
•
•
•
•
CPRES input:
•
•
•
•
•
The microcontroller will exit from Power-down or Idle modes upon a reset or INT1 inter-
rupt which is a multiplexing of the interruptions generated by the CPRES pin (Card
detection), RxD flag (UART reception) and INT1 pin.
Only for AT8xC5122.
or idle mode by software (see Table 13, PCON register). Before activating these modes
the application will need to configure the keyboard interface as follows:
•
The microcontroller will exit from Power-down Mode upon a reset or any interrupt gener-
ated by a key press. Note that 1024 clocks are necessary to exit from power-down mode
when a keyboard interrupt occurs. This means that there will be a delay between the
time at which the key is pressed and the time at which the application is able to identify
the key.
Set CRST pin at low level by clearing the bit CARDRST in SCCON register.
Set CCLK pin at low level by clearing the bit CLK then the CARDCLK in SCCON
register.
Set CIO pin at low level by clearing the bit UART in SCICR register then the bit
CARDIO in SCCON register.
Power the Smart Interface off by clearing the CARDVCC bit in SCCON register. This
instruction enables to switch DC/DC converter off.
Set the bit PRSEN in ISEL register
Set the bit EX1 in IE0 register
Set the bit EA in the IE0 register
Invert the bit CPLEV in ISEL register (INT1 interrupt vector)
Clear the bit PRESIT in the ISEL register
Set all keyboard’s ouputs pins KB Rx at low level by writing a 0 on the ports. This
operation has a double effect:
–
–
any key that is pressed generates an interrupt capable of waking-up the
microcontroller,
Set all bits KBE.x in KBE registers to enable interrupts.
AT8xC5122/23
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