When you disassemble the chip of the SIM card of the smartphone, you can see well that the contents are actually "computer"

"SIM card" inserted in feature phones and smartphones to communicate is a familiar existence common in daily life, but it is surprisingly few people who know about what the inside is like. When you disassemble the SIM card and analyze its contents, you can see that it is a clear computer that has CPU and memory and has been subjected to data security measures.

Decap of a Cell Phone SIM card
https://electronupdate.blogspot.jp/2016/10/decap-of-cell-phone-sim-card.html

The situation of disassembling SIM card for GSM can be confirmed in the following movie.

Decap of a Cell Phone SIM card - YouTube


What kind of device is a SIM card in a mobile phone or smartphone? Disassemble and analyze it.


It is like this when peeling off the plastic layer on the surface of the SIM card and putting the die in the exposed state.


The modules are divided into areas as if they were the latest video controllers.


On the die is the letter "SCF 384 G STARCHIP".


I tried searching on Google and said that it came to a manufacturer called SAFRAN in France.


Further examining the chip type showed that the "SCF 384 G" chip is a computer with a CPU with 384 KB flash memory, 14 KB memory and 25 MHz frequency.


It seems that ARM CPU "APS 3 S" is installed.


By the way, the performance of the computer in 1989 is almost equivalent to the SIM card. In just 25 years the computer has been downsized to the piece size of the card.


The block diagram of the SIM card chip looks like this.


The red part at the bottom left of the die operates at 25 MHz "APS 3 S"


Flash memory is divided into 2 areas for program and data.


The 10 KB memory is stored in the lower right.


Analyze the middle layer of the die with X-rays.


On the right side of the die is a power section.


SIM card has been introduced to security that locks information and makes it impossible to read. The thin and small SIM card chip that comes with the card has become a perfect computer that can run programs on its own.