Specifications

Physical Layer Simplified Specification Version 4.10

3.8 ROM Card

ROM Card is defined as read only memory which meets following requirements. A permanent or

temporary write protected writable SD memory card does not belong to this category.

3.8.1 Register Setting Requirements

Table 3-4 shows register setting requirements for ROM Card.

Field

Value

Comment

SD Status

SD_CARD_TYPE

0001h

SD ROM Card

CSD

CCC bit 4

Class4 block write

CCC bit 5

Class5 erase

CCC bit 6

Class6 write protection

CCC bit 7

0 or 1

Class7 lock card

PERM_WRITE_PROT

Permanent Write Protect

SCR

SD_SECURITY

0 or 2 or 3

Security is optional.

Table 3-4 : Register Setting Requirements for ROM Card

3.8.2 Unsupported Commands

The ROM Card shall treat following commands as unsupported and illegal command.

CMD24, CMD25, CMD27, CMD28, CMD29, CMD30, CMD32, CMD33, CMD38

3.8.3 Optional Commands

The ROM Card can support following commands as optional command.

CMD42, security commands

• If CMD42 is not supported, bit 7 of CCC shall be set to 0. CMD42 is treated as illegal command.

• When ROM card supports CMD42, "Unlocking the card" and "Locking the card" functions shall be

supported by presetting the password. LOCK_UNLOCK_FAILED is indicated when receiving the

other unsupported functions of CMD42.

• If security is not supported, SD_SECURITY shall be set to 0. The security commands are treated

as illegal command.

• ROM card does not support write and erase to the protected area. Refer to the Part 3 Security

Specification about security command support of ROM card.

3.8.4 WP Switch

A full-size ROM card does not have WP Switch.