AT83EC5123 ATMEL Corporation, AT83EC5123 Datasheet - Page 41

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

Power-on and Power-off FSM
4202B–SCR–07/03
In T=1 mode, the CWT (character waiting time) or the BWT (block waiting time) are
loaded in the same registers.
The maximum time between two consecutive start bit is WT[31:0] * ETU.
When used to check BWT according to ISO 7816, WT can be set between 971 and
15728651.
The WT counter is 32 bits wide in order to handle the BWT extension. In this case, WT
must be loaded with the value BWT * WTX.
Figure 22. T=0 mode
Figure 23. T=1 Mode
In this state, the machine applies the signals on the smart card in accordance with
ISO7816 standard.
To be able to power on the SCIB, the card presence is mandatory. Removal of the smart
card will automatically start the power off sequence as described in Figure 24.
The SCI deactivation sequence after a reset of the CPU or after a lost of power supply is
ISO7816 compliant. The switching order of the signals is the same as in Figure 24 but
the delay between signals is analog and not clock dependant.
CHAR 1
< CWT
TRANSMISSION
CHAR 2
BLOC 1
CHAR 1
CHAR n
> GT
< WT
< BWT
CHAR 2
CHAR n+1
< CWT
AT8xC5122/23
RECEPTION
CHAR n+2
BLOC 2
CHAR n+3
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