ST7SCR datasheet(60/102 Pages) STMICROELECTRONICS

60 / 102 page

ST7SCR

60/102

SMARTCARD INTERFACE (Cont’d)

12.4.3.6 Card Deactivation Sequence

This sequence can be activated in two different

ways:

– Automatically as soon as the card presence de-

tector detects a card removal (via the CRDIRF bit

in the CRDSR register, refer to Section 12.4.3.5).

– By software, writing the CRDVCC bit in the CRD-

CR register, for example:

– If there is a smartcard current overflow (i.e.

when the IOVFF bit in the CRDSR register is

set)

– If the voltage is not within the specified range

(i.e. when the VCARDOK bit in the CRDSR

the CRDVCC bit in the CRDCCR register to

start the deactivation sequence.

When the CRDVCC bit is cleared, this starts the

deactivation

sequence.

CRDCLK,

CRDIO,

CRDC4 and CRDC8 pins are then deactivated as

shown in Figure 33:

Figure 33. Card deactivation sequence

Figure 34. Card voltage selection and power OFF block diagram

CRDVCC pin

CRDRST pin

CRDCLK pin

CRDIO pin

CRDC4 pin

CRDC8 pin

8 CPU Clk cycles

CRDVCC

CRD

CRDCCR

BLOCK

VCC

CRDCR

IRF

CRDSR

CRD

VCARD

POWER OFF

IOVF

CRDIER

CRDIPR

IOVP VCRD

SMARTCARD

POWER SUPPLY

BLOCK

VCARDOK Interrupt Request

IOVF Interrupt Request

Card voltage selection

IOVM VCRD

VCARD

ST7SCR Datasheet(PDF) 60 Page - STMicroelectronics

ST7SCR Datasheet(HTML) 60 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL