SDMJ-32 SanDisk, SDMJ-32 Datasheet - Page 50

• Manufacturer Part Number: SDMJ-32
• Manufacturer: SanDisk
• Type: MultiMedia Cardr

Specifications of SDMJ-32

• Density: 32MByte
• Operating Supply Voltage (typ): 3.3V
• Operating Temperature (min): -25C
• Operating Temperature (max): 85C
• Package Type: MMC
• Mounting: Socket
• Pin Count: 7
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Programmable: Yes
• Lead Free Status / RoHS Status: Compliant

Revision 1.3
© 2005 SanDisk Corporation
4.4.2
CRC16
Figure 4-3
The CRC16 is used for payload protection in block transfer mode. The CRC checksum is a
16-bit value and is computed as follows:
All CRC registers are initialized to zero. The first bit is the first data bit of the
corresponding block. The degree n of the polynomial denotes the number of bits of the data
block decreased by one. For example, n = 4,095 for a block length of 512 bytes. The
generator polynomial G(x) is a standard CCITT polynomial. The code has a minimal
distance d=4 and is used for a payload length of up to 2,048 bytes (n < 16,383).
Figure 4-4
generator polynomial: G(x) = x
M(x) = (first bit) * x
CRC[15...0] = Remainder [(M(x) * x
CRC7 Generator/Checker
CRC16 Generator/Checker
n
+ (second bit) * x
4-12
16
+ x
MultiMediaCard/RS-MultiMediaCard Product Manual
12
16
Chapter 4 – MultiMediaCard Protocol Description
) / G(x)]
+ x
n-1
+...+ (last bit) * x
5 +1
0
04/22/05