AT89C5122 ATMEL [ATMEL Corporation], AT89C5122 Datasheet - Page 183

• Manufacturer Part Number: AT89C5122
• Description: MICROCONTROLLER WITH USB AND SMART CARD READER INTERFACES
• Manufacturer: ATMEL [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
4202D–SCR–06/05
Detection of a SUSPEND State
Detection of a RESUME State
Note :
WUPCPU bit must be
Cleared before enabling
the PLL
Figure 110. Example of a Suspend/Resume Management
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.
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
WUPCPU
SPINT
microcontroller in power-down
Clear WUPCPU bit
USB Controller Init
Clear SUSPCLK
Set SUSPCLK
Disable PLL
Enable PLL
Clear SPINT
Put the USB pads
in power down mode
183