SD Card Interface Description
SanDisk Secure Digital (SD) Card Product Manual, Rev. 1.9 © 2003 SANDISK CORPORATION
3-11
Parameter Symbol
Min.
Max.
Unit
Remark
Inputs CMD, DAT (referenced to CLK)
Input set-up time
t
ISU
5 ns
C
L
≤
25 pF
(1 cards)
Input hold time
t
IH
5 ns
C
L
≤
25 pF
(1 cards)
Outputs CMD, DAT (referenced to CLK)
Output delay time during Data Transfer Mode
t
ODLY
0 14 ns
C
L
≤
25 pF
(1 cards)
Output delay time during Identification Mode
t
ODLY
0 50 ns
C
L
≤
25 pF
(1 cards)
NOTE: OHz stops the clock. The given minimum frequency range is for cases where a continuous clock is required.
3.5. SD Card Registers
There is a set of seven registers within the card interface. The OCR, CID, CSD and SCR registers carry the card
configuration information. The RCA register holds the card relative communication address for the current session.
The card status and SD status registers hold the communication protocol related status of the card.
3.5.1. Operating Conditions Register (OCR)
The 32-bit operation conditions register stores the V
DD
voltage profile of the card. The SD Card is capable of
executing the voltage recognition procedure (CMD1) with any standard SD Card host using operating voltages form
2 to 3.6 Volts.
Accessing the data in the memory array, however, requires 2.7 to 3.6 Volts. The OCR shows the voltage range in
which the card data can be accessed. The structure of the OCR register is described in Table 3-8.
Table 3-8. OCR Register Definition
OCR Bit
VDD Voltage Window
0-3 Reserved
4 1.6-1.7
5 1.7-1.8
6 1.8-1.9
7 1.9-2.0
8 2.0-2.1
9 2.1-2.2
10 2.2-2.3
11 2.3-2.4
12 2.4-2.5
13 2.5-2.6
14 2.6-2.7
15 2.7-2.8
16 2.8-2.9
