hb28d064mm2 Renesas Electronics Corporation., hb28d064mm2 Datasheet - Page 6

• Manufacturer Part Number: hb28d064mm2
• Description: Multimediacard 16 Mbyte/32 Mbyte/64 Mbyte/128 Mbyte
• Manufacturer: Renesas Electronics Corporation.

HB28E016/D032/D064/B128MM2
SPI Mode
The Serial Peripheral Interface (SPI) is a general-purpose synchronous serial interface originally found on
certain Motorola microcontrollers. The MultiMediaCard SPI interface is compatible with SPI hosts
available on the market. As any other SPI device the MultiMediaCard SPI interface consists of the
following four signals:
CS: Host to card Chip Select signal.
CLK: Host to card clock signal
Data in: Host to card data signal.
Data out: Card to host data signal.
The MultiMediaCard card identification and addressing methods are replaced by a hardware Chip Select
(CS) signal. There are no broadcast commands. For every command, a card (slave) is selected by asserting
(active low) the CS signal (refer to Figure “SPI Bus System”). The CS signal must be continuously active
for the duration of the SPI transaction (command, response and data). The only exception occurs during
card programming, when the host can de-assert the CS signal without affecting the programming process.
The bidirectional CMD and DAT lines are replaced by unidirectional data in and data out signals. This
eliminates the ability of executing commands while data is being read or written and, therefore, makes the
sequential and multi block read/write operations obsolete. The single and multiple block read/write
commands are supported by the SPI channel. The SPI interface uses the same seven signals of the standard
MultiMediaCard bus (refer to Table “SPI Interface Pin Configuration”).
6
Power
supply
SPI bus (CLK, Datain, Dataout)
SPI card
SPI Bus System
SPI card
SPI bus master
CS
CS