HB288032MM1 Datasheet, PDF (76/80 Pages) Hitachi Semiconductor – MultiMediaCard 32 MByte

HB288032MM1
Access Time
Parameter
Symbol Typ
Synchronous access delay cycles N_SAD
—
Synchronous access delay
T_SAD
—
Asynchronous access delay
T_AAD
300
Memory access time
t _AT
300.8
Note: 1. Refer to Chapter “Time-out Condition”.
Max
16
0.8
—
—*¹
Unit
cycles
µs
µs
µs
Remark
at 20 MHz clock frequency
at 20 MHz clock frequency
In the CSD are two fields to code the asynchronous and the synchronous access delay time:
• TAAC, asynchronous access delay
• NSAC, maximum number of cycles for receiving and interpreting of a command frame
The value for the CSD field NSAC is calculated from N_SAD (maximum: 16 cycles) by division with 100
and rounding up to the next integer:
NSAC = [N_SAD/100] = [16/100]
• NSAC = 0x01
The value for the CSD field TAAC is 1 ms:
TAAC = [T_AAD] = 1 ms
• TAAC = 0x0E
For more details on NSAC and TAAC CSD-entries refer to Chapter “Card Specific Data (CSD)”.
References
[1] The MultiMediaCard, System Specification 2.11, MultiMediaCard Association
Number Representations
• decimal numbers: 1234, no special characters
• hexadecimal numbers: 0xAB, leading 0x, each digit represents 4 bits.
• binary numbers (single bit): ‘0’.
• binary number (unsigned bit vector): “100100”.
• 1k is equal to 1024.
• 1M is equal to 1k*1k.
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