AT83C24 ATMEL Corporation, AT83C24 Datasheet - Page 3

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

Pin Description
Pinouts (Top View)
Signals
Table 1. Ports Description
4234E–SCR–09/04
Pad Name
PRES/INT
A1/RST-
RESET
A2/CK-
A0/3V
Power Supply
Pad Internal
EVCC
EVCC
VCC
Limits
Note:
ESD
3 kV
3 kV
3 kV
CMDVCC
CVCCin
RESET
DVCC
CVSS
CVCC
CCLK
VCC
CRST
1. NC = Not Connected
2. SOIC and QFN packages are available for
VSS
CC4
Type
open-
open-
NC
Pad
drain
drain
C8
LI
I/O
O
I
14
4
10
12
1
3
5
6
7
11
13
2
8
9
28-pin SOIC Pinout
Description
Microcontroller Interface Function:
TWI bus slave address selection input.
A2/CK and A1/RST pins are respectively connected to CCLK and CRST signals in
“transparent mode” (see page 18 ).
A0/3V is used for hardware activation to select CVCC voltage (3V or 5V).
The slave address of the device is based on the value present on A2, A1, A0 on the
rising edge of RESET pin (see Table 2). In fact, the address is taken internally at the 11th
CLK rising edge.
Microcontroller Interface Function:
Depending on IT_SEL value (see CONFIG4 register),
PRES/INT outputs card presence status or interruptions (page 9)
An internal Pull-up (typ 330k see Table 18)to EVCC can be activated in the pad if
necessary using INT_PULLUP bit (CONFIG4 register).
Remark: during power up and before registers configuration, the PRES/INT signal must
be ignored.
Microcontroller Interface Function:
•
•
•
•
Power-on reset
A low level on this pin keeps the AT83C24 under reset even if applied on power-on.
It also resets the AT83C24 if applied when the AT83C24 is running (see Power
monitoring §).
Asserting RESET when the chip is in Shut-down mode returns the chip to normal
operation.
AT83C24 is driving the Reset pin Low on power-on-reset or if power fail on V
DVCC (see POWERMON bit in CONFIG4 register), this can be used to reset or
interrupt other devices. After reset, AT83C24 needs to be reconfigured before
starting a new card session.
28
24
22
21
27
26
25
23
20
19
18
17
16
15
NC
CIO
EVCC
SCL
SDA
CC8
CLK
C4
CPRES
I/O
A2
A1
A0
PRES/INT
/CK
/RST
/3V
CMDVCC
CVCCin
CVCC
AT83C24 and for AT83C24NDS
CVSS
VSS
V
LI
CC
1
6
7
2
3
5
4
28
8
QFN28 pinout
27
9 10 11 12 13 14
TOP VIEW
26
QFN 28
25
24
AT83C24
23
22
20
19
18
16
21
17
15
NC
SDA
EVCC
SCL
A2
A1
A0
/RST
/CK
/3V
CC
or
3