Specifications

Physical Layer Simplified Specification Version 4.10

3. SD Memory Card System Concept

Description here is a blank in the Simplified Specification.

3.1 Read-Write Property

In terms of read-write property, two types of SD Memory Cards are defined:

• Read/Write (RW) cards (Flash, One Time Programmable - OTP, Multiple Time Programmable - MTP).

These cards are typically sold as blank (empty) media and are used for mass data storage, end user

video, audio or digital image recording

• Read Only Memory (ROM) cards. These cards are manufactured with fixed data content. They are

typically used as a distribution media for software, audio, video etc.

3.2 Supply Voltage

In terms of operating supply voltage, two types of SD Memory Cards are defined:

• High Voltage SD Memory Cards that can operate the voltage range of 2.7-3.6 V.

• UHS-II SD Memory Card that can operate the voltage ranges VDD1: 2.7-3.6 V, VDD2: 1.70-1.95V

3.3 Card Capacity

3.3.1 User Area and Protected Area

SD Memory Card has two accessible independent areas: User Area and Protected Area. User Area is

main memory area and Protected Area can be accessed by the authentication defined by the Part 3

Security Specification. Card Capacity means the sum of User Area Capacity and Protected Area

Capacity.

3.3.2 Card Capacity Classification

In terms of card capacity, three types of SD Memory Cards are defined:

• Standard Capacity SD Memory Card (SDSC) supports capacity up to and including 2 G bytes (2

bytes). All versions of the Physical Layer Specifications define the Standard Capacity SD Memory

Card.

• High Capacity SD Memory Card (SDHC) supports capacity more than 2 G bytes (2

bytes) up to 32

G bytes and is defined from the Physical Layer Specification Version 2.00.

• Extended Capacity SD Memory Card (SDXC) supports more than 32 G bytes (2

bytes) up to 2TB.

Note:

1. The Part 1 Physical Layer Specification Version 3.00 or later and Part 2 File System Specification

Version 3.00 or later allow Standard Capacity SD Memory Cards to have capacity up to and including

2 GB, High Capacity SD Memory Cards to have capacity up to and including 32 GB and Extended

Capacity SD Memory Card to have capacity up to 2 TB.

2. Hosts that can access (read and/or write) SD Memory Cards with a capacity greater than 2 GB and up

to and including 32 GB, shall also be able to access SD Memory Cards with a capacity of 2 GB or

less.

3. Hosts that can access (read and/or write) SD Memory Cards with a capacity greater than 32 GB and

up to 2 TB, shall also be able to access SD Memory Cards with a capacity of 32 GB or less.

3.4 Speed Class

Five Speed Classes are defined and indicate minimum performance of the cards

• Class 0 - These class cards do not specify performance. It includes all the legacy cards prior to

the Physical Layer Specification Version 2.00, regardless of its performance