Echelon FT 3150 Smart Transceiver - Manual (Page 51)

FT 3120 / FT 3150 Smart Transceiver Data Book 45
Parallel I/O Objects
Figure 3.14 Nibble Output Latency Values
Parallel I/O Objects
Muxbus Input/Output
This I/O object provides a means of performing parallel I/O data transfers between the FT Smart Transceiver and an
attached peripheral device or processor (see Figure 3.15). Unlike the parallel input/output object, which makes use of
a token-passing scheme for ensuring synchronization, the muxbus input/output enables the FT Smart Transceiver to
essentially be in control of all read and write operations at all times. This relieves the burden of protocol handling
from the attached device and results in an easier-to-use interface at the expense of data throughput capacity. The data
bus remains in the last state used.
Symbol Description Typ @ 10MHz
t
fout
Function to update
IO0
IO1
IO2
IO3
IO4 78 µs
89.8 µs
101.5 µs
113.3 µs
125 µs
t
ret
Return from function
IO0 – IO4 5 µs
OUTPUT PIN
UPDATED
END OF
io_out()
START OF
io_out()
t
ret
t
fout
TIME
OUTPUT