User Manual

TriFlash Interface Description

Figure 3-2 shows the bus topology of several devices with one host in SD Bus mode.

Figure 3-2. TriFlash System Bus Topology

During the initialization process, commands are sent to each device individually, allowing the application to detect

the devices and assign logical addresses to the physical slots. Data is always sent to each device individually.

However, to simplify the handling of the card stack, after initialization, all commands may be sent concurrently to

all devices. Addressing information is provided in the command packet.

The SD Bus allows dynamic configuration of the number of data lines. After power-up, by default, the TriFlash will

use only DAT0 for data transfer. After initialization, the host can change the bus width (number of active data

lines). This feature allows an easy trade off between hardware cost and system performance.

TriFlash (A)

CLK

Vdd

Vss

D0-D3, CMD

SD Memory

Card (B)

CLK

Vdd

Vss

D0-D3, CMD

MultiMediaCard

(C)

CLK

Vdd

Vss

D0, CS, CMD

CLK

Vdd

Vss

D0-3(A),

CMD(A)

D0-3(B),

CMD(B)

D0-3(C)

CMD(C)

HOST

D1&D2 Not

Connected