hb28j128mm3 Renesas Electronics Corporation., hb28j128mm3 Datasheet - Page 36

• Manufacturer Part Number: hb28j128mm3
• Description: Multimediacard 32 Mbyte/64 Mbyte/128 Mbyte/256 Mbyte/512 Mbyte
• Manufacturer: Renesas Electronics Corporation.

HB28K032/L064/J128/J256/J512MM3, HB28K032/L064/J128/J256RM3
ends with an end bit (HIGH). The data transmission is synchronous to the clock signal. The payload for
block-oriented data transfer is preserved by a 16-bit CRC check sum (refer to Chapter “Cyclic Redundancy
Check (CRC)”).
There is a stream oriented data transfer controlled by READ_DAT_UNTIL_STOP (CMD11). This
command instructs the card to send its payload, starting at a specified address, until the host sends a
STOP_TRANSMISSION command (CMD12). The stop command has an execution delay due to the serial
command transmission. The data transfer stops after the end bit of the stop command. If the end of the
memory range is reached while sending data and no stop command has been sent yet by the host, the
contents of the further transferred payload is undefined. The maximum clock frequency for stream read
operation is given by the following formula:
these parameters being defined in Chapter “Registers”. If the host attempts to use a higher frequency, the
card may not be able to sustain data transfer. If this happens, the card will set the UNDERRUN error bit in
the status register, abort the transmission and wait in the data state for a stop command.
The basic unit of data transfer is a block whose maximum size is defined in the CSD (READ_BLK_LEN).
READ_BLK_PARTIAL is set, thus smaller blocks whose starting and ending address are wholly contained
within one physical block (as defined by READ_BLK_LEN) may also be transmitted. A 16-bit CRC is
appended to the end of each block ensuring data transfer integrity. READ_SINGLE_BLOCK (CMD17)
starts a block read and after a complete transfer the card goes back to Transfer State.
READ_MULTIPLE_BLOCK (CMD18) starts a transfer of several consecutive blocks. Two types of
multiple block read transactions are defined (the host can use either one at any time):
The host can abort reading at any time, within a multiple block operation, regardless of the its type.
Transaction abort is done by sending the stop transmission command.
Rev.0.02, Sep.15.2004, page 36 of 89
Stream read
Block read
The number of blocks for the read multiple block operation is not defined. The card will
continuously transfer data blocks until a stop transmission command is received.
The card will transfer the requested number of data blocks, terminate the transaction and return to
transfer state. Stop command is not required at the end of this type of multiple block read, unless
terminated with an error. In order to start a multiple block read with pre-defined block count, the
host must use the SET_BLOCK_COUNT command (CMD23) immediately preceding the
READ_MULTIPLE_BLOCK (CMD18) command. Otherwise the card will start an open-ended
multiple block read which can be stopped using the STOP_TRANSMISSION command.
max. speed = min (TRAN_SPEED, (8 * 2
Open-ended Multiple block read
Multiple block read with pre-defined block count
= min (20, (8 * 2
= min (20, 3.996) 3.996 [MHz]
9
)
100 [cycles]) / 1000 [ s]) [MHz]
READ_BL_LEN
NSAC) / TAAC),