4 1.8V technology

11.183GPPSpecification of the 1.8 Volt Subscriber Identity Module - Mobile Equipment (SIM - ME) InterfaceTS

4.1 1.8V technology SIM

The SIM shall operate on both 3V ± 10% according to GSM 11.12 [2], and on 1.8V ± 10% according to the present document. If the ME supplies 3V to the SIM, both the ME and the SIM shall operate according to GSM 11.12 (ETS 300 641) [2]. The logical operation of the 1.8V technology SIM shall be as defined in GSM 11.11 [1]. The 1.8V technology SIM shall not give an ATR if operated at a supply voltage of 1.4V or below.

A 1.8V technology SIM may operate at 5V. If the 1.8V technology SIM operates at 5V it shall meet the electrical specifications as defined in GSM 11.11 [1].

Clock stop mode shall be supported by the SIM. The SIM shall indicate "Clock Stop Allowed" in the file characteristics of the status information as specified in GSM 11.11 [1].

4.2 1.8V technology impact

When supplied with the supply voltage as specified in the present document the SIM shall be operated with a clock frequency of 1 to 4 MHz.

4.3 1.8V technology SIM Identification

The 1.8V technology SIM shall contain an identification. The identification is coded on bits 5-7 in byte 14 of the status information as follows:

Table 0: SIM Supply Voltage Indication

SIM Supply Voltage

Bit 7

Bit 6

Bit 5

5V only SIM

0 (RFU) 1

0 (RFU) 1

0 (RFU) 1

3V Technology SIM

0 (RFU) 1

0 (RFU) 1


1.8V Technology SIM

0 (RFU) 1



Future Class




NOTE 1 The bits marked (RFU) are set to ‘0’ and reserved for future use in the SIMs. The coding schemes relies on the fact that RFU bits are set to ‘0’.

The procedure for deriving the identification bit shall be performed by the ME immediately after the Answer To Reset (ATR) and before issuing any other command. The procedure consists of the two commands "SELECT GSM" and "STATUS/GET RESPONSE"

4.4 1.8V technology ME

The 1.8V technology ME shall initially activate the SIM with 1.8V according to this specification.

If the ME detects a 1.8V technology SIM, the ME may operate the SIM at 1.8V according to this specification. If the ME detects a 3V SIM, the ME shall switch to 3V operation as defined in GSM 11.12 [2] using the procedure as defined in subclause 4.7. If switching is performed, it shall take place before issuing any further commands as defined in paragraph 4.3.

If a faulty ATR is received at 1.8V, the ME shall initiate the error handling procedure described in GSM 11.11 [1] with the supply voltage remaining at 1.8V. If the error handling does not result in an errorless ATR, the ME shall activate the SIM at 3V. Activation at 3V shall be performed in accordance with GSM 11.12 [2].

If no ATR is received at 1.8V, the ME shall deactivate the SIM and activate it at 3V according to GSM 11.12 [2]. If a correct ATR is not received at 3V or the ME detects a 5V only SIM the ME shall reject the SIM without issuing any further commands.

If a 1.8V technology ME detects a SIM that indicates a future class the ME shall not activate that SIM at 3V.

4.5 1.8V Only ME

The 1.8V only ME activates the SIM at 1.8V.

If the ME is able to detect a 3V technology SIM according to the procedure in subclause 4.3, or if the procedure cannot be completed, the ME shall deactivate and reject the SIM immediately (maximum of 5s) without issuing any further command.

If an ATR is corrupted or not received by the ME, error handling according to sub clause 5.10 of GSM 11.11 [1] shall apply.

4.6 Activation and deactivation

The ME shall connect, activate and deactivate the SIM in accordance with the operating procedures specified in GSM 11.11 [1] taking into account the electrical characteristics specified in clause 5 of the present document. In particular, Vcc is powered when it has a value between 1,62 V and 1,98 V.

4.7 Supply voltage switching

MEs supporting both 1,8V and 3V operation may switch between the two supply voltages. Switching shall always be performed by deactivating the SIM and activating it at the new supply voltage. Activation and deactivation of the SIM with 3V shall be according to GSM 11.12 [2], whereas activation and deactivation of the SIM with 1,8V shall be according to the present document.

4.8 Cross compatibility

Cross compatibility means that the ME supports 1,8V and 3V operation. This is, however, optional for the ME. In case of the 1,8V technology ME, cross compatibility is provided, whereas, a 1,8V only ME requires a 1,8V technology SIM for operation. However, the 1,8V technology SIM (see definitions and subclause 4.1) ensures cross compatibility.