AT83EC5123 ATMEL Corporation, AT83EC5123 Datasheet - Page 43

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

Additional Features
Clock
Alternate Card
4202B–SCR–07/03
The CK_ISO input must be in the range 1 - 5 MHz according to ISO 7816.
The CK_ISO can be programmed up to 12 MHz. In this case, the timing specification of
the output buffer will not comply to ISO 7816.
Figure 26. Clock Diagram of the SCIB Block
Figure 27. Prescaler 2 Description
The division factor SCICLK must be smaller than 49. If it is greater or equal to 49, the
PR2 prescaler is locked.
Table 37. Examples of Settings Ffor Clocks
A second card named ‘Alternate Card’ can be controlled.
XTAL1 (MHz)
48
8
8
8
8
8
8
XTSCS
EXT48
PLLCON.2
SCCLK.7
FCK_IDLE
FCK_PLL or
FCK_XTAL1
EXT48
CK_PLL
CK_XTAL1
1
0
0
0
0
0
0
0
1
PR2
/ (2 * (48 - SCICLK[5-0]))
SCICLK
42
36
44
42
40
24
0
PR2
Ck_cpu
Ck_ISO
SCIB
AT8xC5122/23
SCICLK.[5:0]
=48
0
1
CK_ ISO
CK_ISO
12
4
4
8
6
2
1
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