Chapter 3 – SD Card Interface Description
Revision 2.2
SD Card Product Manual
© 2004 SanDisk Corporation
3-17
12/08/04
•
DSR_IMP
—defines if the configurable driver stage is integrated on the card. If set, a
Driver Stage Register (DSR) must also be implemented.
Table 3-20
DSR Implementation Code Table
DSR_IMP DSR
Type
0
No DSR implemented
1 DSR
implemented
•
C_SIZE (Device Size)
—computes the card capacity. The memory capacity of the card
is computed from the entries C_SIZE, C_SIZE_MULT and READ_BL_LEN as
follows:
memory capacity =
BLOCKNR * BLOCK_LEN
Where:
BLOCKNR
=
(1)
*
MULT
MULT = 2
C_SI2
(C_SIZE_MULT < 8)
BLOCK_LEN
=
2
READ_BL_LEN
(READ_BL_LEN < 12)
Therefore, the maximum capacity that can be coded is 4096*512*2048=4 GB. For
example, a 4-MB card with BLOCK_LEN = 512 can be coded with C_SIZE_MULT =
0 and C_SIZE = 2047.
•
VDD_R_CURR_MIN, VDD_W_CURR_MIN
—minimum values for read and write
currents at the VDD power supply are coded in Table 3-21.
Table 3-21
V
DD
Minimum Current Consumption
VDD_R_CURR MIN
VDD_W_CURR MIN
Code for Current Consumption @ V
DD
2:0
0=0.5 mA, 1=1 mA, 2=5 mA, 3=10 mA, 4=25 mA, 5=35 mA, 6=60 mA, 7=100
mA
•
VDD_R_CURR_MAX, VDD_W_CURR_MAX
—maximum values for read and
write currents on VDD power supply are coded Table 3-22.
Table 3-22
V
DD
Maximum Current Consumption
VDD_R_CURR MAX
VDD_W_CURR MAX
Code for Current Consumption @ V
DD
2:0
0=1 mA, 1=5 mA, 2=10 mA, 3=25 mA, 4=35 mA, 5=45 mA, 6=80 mA, 7=200
mA
•
C_SIZE_MULT (Device Size Multiplier)
—codes a factor MULT for computing the
total device size (see C_SIZE). The factor MULT is defined as 2
C_SI2
.
