sc23m42 Silan, sc23m42 Datasheet - Page 4

• Manufacturer Part Number: sc23m42
• Description: 256-byte Memory Card Ic
• Manufacturer: Silan

FUNCTION DESCRIPTIONS
the former 32-bit bytes. Except PSC (Programmable Security Code) memory unit, all units are readable. The unit
can be erased and written before the write-protect is active, or else the unit is only readable after the write-protect.
The bit with write-protection can be programmed only once, and cannot be erased. The chip has one 3-bit (bit0-
bit2)error register which provides 3 times continuous PSC authentication at most, after 3 times the chip cannot be
erased and written.
Transmission Protocols
1. Reset and reset acknowledge
The reset signal begins when RST changed from“ 0” to “ 1” and end when CLK changed from “ 0” to“ 1” . The reset
signal can stop any active instruction. Read operation must be carried out first after power on reset, then the
other operations.
automatically and will send the first data to the I/O port. As the clock signal, the address data can be read serially.
And the content of the former 4 EEPROM address units can be read after the continuous 32 clock pulses, and
then the 33
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Reset acknowledge
SC23M42 provides 256×8 bits EEPROM memory units and 32×1 protect units, and there is writing-protect for
Transmit the data by serial two buses between IFD and IC memory cards.
The transmission protocols can be defined as four operation mathods
The chips enter the power on reset state when it is power on, and this state will be ended by the reset signal.
The reset acknowledge complies to ISO7816-3 synchronous propagation. The address counter is set to “ 0”
-Reset and reset acknowledge
-Command
-Output the data
-Process
(Hex)
rd
clock pulse will set I/O to H state. The details refer to the figure 1.
DO
Byte 1
7
… DO
Figure 1 Reset and reset acknowledge
0
DO
Byte2
15
… DO
8
DO
Byte3
23
… DO
16
REV:1.0
DO
SC23M42
Byte4
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… DO
2006.07.21
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