AT83C24-PRRIL ATMEL [ATMEL Corporation], AT83C24-PRRIL Datasheet - Page 18

• Manufacturer Part Number: AT83C24-PRRIL
• Description: Smart Card Reader Interface with Power Management
• Manufacturer: ATMEL [ATMEL Corporation]

Transparent Mode
18
AT83C24
Notes:
If the microcontroller outputs ISO 7816 signals, a transparent mode allows to connect
RST/CLK and I/O/C4/C8 signals after an electrical level control. The AT83C24 level
shifters adapt the card signals to the smart card voltage selection.
The CRST and CCLK microcontroller signals can be respectively connected to the
A1/RST and A2/CK pins.
The CRST_SEL bit (in CONFIG4 register) selects standard or transparent configuration
for the CRST pin. CKS in CONFIG2 allows to select standard or transparent configura-
tion for the CCLK pin. So CCLK and CRST are independent. A2/CK to A0/3V inputs
always give the TWI address at reset. The A0/3V pin can be used for TWI addressing
and easily connect two AT83C24 devices on the same TWI bus.
Figure 13. Deactivation Sequence
Figure 14. Transparent Mode Description
Microcontroller
1. Setting ICARDERR by software does not trigger a deactivation. VCARDERR can be
2. t1=5 to 5.5*Td, and t2=0.5*Td to Td.
CCLK
CRST
CIO
CC4
CC8
used to deactivate the card by software.
CCLK
CRST
CVCC
CIO,
CC4,
CC8
A1/RST
A2/CK
t1
I/O
C4
C8
AT83C24
t2
Td
CCLK
CRST
CIO
CC4
CC8
SMART CARD
4234E–SCR–09/04