Specifications

Chapter 3 – Input/Output Interfaces
48 PL 3120/PL 3150/PL 3170 Power Line Smart Transceiver Data Boo
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Byte Input/Output
Pins IO0 – IO7 can be configured as a byte-wide input or output port, which can be read or written using integers in the
range 0 to 255. This is useful for driving devices that require ASCII data, or other data, eight bits at a time. For example,
an alphanumeric display panel can use byte function for data, and use pins IO8 – IO11 in bit function for control and
addressing. See Figures 3.8, 3.9, and 3.10. IO0 represents the LSB of data. The direction of a byte port can be changed
between input and output dynamically under application control. (io_set_direction())
Figure 3.8 Byte I/O
TIME
INPUT PIN
SAMPLED
END OF
io_in()
START OF
io_in()
INPUT
t
fin
t
ret
Symbol Description Typ @ 10MHz
t
fin
Function call to input sample 24 µs
t
ret
Return from function 4 µs
Figure 3.9 Byte Input Latency Values
OUTPUT PIN
UPDATED
END OF
io_out()
START OF
io_out()
TIME
OUTPUT
t
fout
t
ret
Symbol Description Typ @ 10MHz
t
fout
Function call to update 57 µs
t
ret
Return from function 5 µs
Figure 3.10 Byte Output Latency Values
IO10
IO9
IO8
IO0
IO1
IO2
IO3
IO4
IO5
IO6
High Current Sink Drivers Optional Pull-Up Resistors
IO10
IO9
IO8
IO0
IO1
IO2
IO3
IO4
IO5
IO6
IO7 IO7
IO11
IO11