NXP Semiconductors freescale semiconductor ColdFire MCF51CN128 Series, Reference Manual

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Mini-FlexBus
11-15 Freescale Semiconductor
MCF51CN128 Reference Manual, Rev. 6
Figure 11-12 illustrates the basic word read transfer to a 16-bit device with no wait states. The address is
driven on the full FB_AD[19:0] bus in the first clock. The device tristates FB_AD[ on the second
clock and continues to drive the address on FB_AD[ ] throughout the bus cycle. The external device
returns the read data on FB_AD[15:0].
NOTE
In non-multiplexed mode, the Mini-FlexBus does not support connection to
a 16-bit device.
Figure 11-12. Single Word-Read Transfer
Figure 11-13 shows the similar configuration for a write transfer. The data is driven from the second clock
on FB_AD[15:0].
NOTE
In non-multiplexed mode, the Mini-FlexBus does not support connection to
a 16-bit device.
15:0]
19:16
FB_CLK
S0 S1 S2 S3
FB_AD[15:0]
FB_R/W
FB_ALE
FB_AD[19:16]
DATA[15:0]
ADDR[19:16]
ADDR[15:0]
Mux’d Bus
FB_CS n , FB_OE
S0