AT83EC5123 ATMEL Corporation, AT83EC5123 Datasheet - Page 38

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

Block Diagram
Functional Description
Barrel Shifter
38
AT8xC5122/23
The Smart Card Interface Block diagram is shown Figure 18:
Figure 18. SCIB Block Diagram
The architecture of the Smart Card Interface Block can be detailed as follows:
The Barrel Shifter allows the translation between 1 bit serial data and 8 bits parallel data
The barrel function is useful for character repetition since the character is still present in
the shifter at the end of the character transmission.
This shifter is able to shift the data in both directions and to invert the input or output
value in order to manage both direct and inverse ISO7816-3 convention.
Coupled with the barrel shifter there is a parity checker and generator.
There are 2 registers connected to this barrel shifter, one for the transmission and one
for the reception. They act as buffers to relieve the CPU of timing constraints.
Clk_iso
Clk_cpu
INT
Waiting time counter
Guard time counter
Etu counter
Interrupt generator
SCI Registers
Barrel shifter
Scart
fsm
Power on
Power off
fsm
I/O
mux
4202B–SCR–07/03
IO (in)
IO (out)
CLK
RST
C4 (out)
C8 (out)
CLK1
C4 (in)
C8 (in)
VCARD