Digi NS9750 - Manual (Page 493)

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B B u s B r i d g e
Figure 75 shows the four functions of the BBus bridge in relation to the AHB bus and
the BBus.
Figure 75: Basic block diagram
Bridge control logic
BBus bridge control logic translates the AHB bus protocol to the BBus protocol and
vice versa. The AHB bus can operate at a maximum of 100MHz; the BBus operates at
half the AHB clock frequency.
Figure 76 details BBus bridge control logic.
AHB Module A AHB Module N AHB Module B
. . . .
BBUS Module A
AHB Memory
Controller
BBUS Module B BBUS Module N
. . . .
AMBA AHB Bus
NetSilicon BBUS
External Mem #1
External Mem #N
External
Peripheral
. .
.
BBUS Bridge
Module
NS9750 ASIC
Bridge
BBUS
Control
AHB
DMA
SPI
Boot