at83c26 ATMEL Corporation, at83c26 Datasheet - Page 39

• Manufacturer Part Number: at83c26
• Description: Multiple Smart Card Reader Interface With Power Management
• Manufacturer: ATMEL Corporation

Table 19. SC1_CFG2 (Config Byte 2 for SC1)
7511D–SCR–02/07
Bit Number
2-0
7
6
5
4
3
7
0
Bit Mnemonic
SHUTDOWNA
CARDDET1
CDS1[2:0]
PULLUP1
ART1
DCK2
X
6
Reset value = 0x X000 1010
Description
Automatic Reset Transition
Set this bit to have the CRST1 pin changed according to activation sequence.
Clear this bit to have the CRST1 pin immediately following the value programmed in CARDRST1.
Shutdown DC/DCA
Set this bit to reduce the power consumption. An automatic de-activation sequence will be done.
VCARD[1:0] bits are reset.
Clear this bit to enable VCARD1[1:0] selection.
Card Presence Detection Polarity
Set this bit to indicate the card presence detector is closed when no card is inserted (CPRES is low).
Clear this bit to indicate the card presence detector is open when no card is inserted (CPRES is high).
Pull-up Enable
Set this bit to enable the internal pull-up on the CPRES pin. This allows to minimize the number of external
components.
Clear this bit to disable the internal pull-up and minimize the power consumption when the card detection
contact is on. Then an external pull-up must be connected to V
Card Detection filtering
CPRES1 is sampled by the master clock provided on CLK input. A change on CPRES1 is detected after:
Note:
CDS1[2-0] = 0: no sample
CDS1[2-0] = 1: 4 identical samples
CDS1[2-0] = 2: 8 identical samples (reset value)
CDS1[2-0] = 3: 16 identical samples
CDS1[2-0] = 4: 32 identical samples
CDS1[2-0] = 5: 64 identical samples
CDS1[2-0] = 6: 128 identical samples
CDS1[2-0] = 7: 256 identical samples
DCK1
5
1.
When CDS[2-0] = 0, a card insertion (even if CLK is stopped) puts a low level on INT pin. This
can be used to wake up the external micro controller and restart CLK when a card is inserted
in the AT83C24.
DCK0
(1)
4
X
3
CKS12
2
CC
(typically a 1 MΩ resistor).
CKS11
1
AT83C26
CKS10
0
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