Specifications

Chapter 3 – Input/Output Interfaces
64 PL 3120/PL 3150/PL 3170 Power Line Smart Transceiver Data Boo
k
Serial Data
Clock
IO10
IO9
IO8
IO0
IO1
IO2
IO3
IO4
IO5
IO6
IO7
CLOCK
(IO8)
TIMEOUT
DATA
(IO9)
TIME
START OF
io_in()
END OF
io_in()
Timeout
t
hold
IO11
t
high
t
setup
t
clk
t
low
t
wto
t
ret
t
tret
t
fin
Symbol Description Min Typ Max
t
fin
Function call to first clock input — 45.0 µs —
t
hold
Data hold 0 µs — —
t
setup
Data setup 0 µs — —
t
low
Clock low width 60 µs — —
t
high
Clock high width 60 µs — —
t
wto
Width of timeout pulse 60 µs — —
t
clk
Clock period 120 µs — —
t
tret
Return from timeout 21.6 µs — 81.6 µs
t
ret
Return from function — — 301.8 µs
Figure 3.25 Magcard Input Object
A PL Smart Transceiver operating at 10MHz can process a bit rate at up to 8334 bits/second (of a bit density of 75
bits/inch). This equates to a card velocity of 111 inches/second. Most magnetic card stripes contain a 15-bit sequence of
zero data at the start of the card, allowing time for the application to start the card reading function. At 8334 bits/second,
this period is about 1.8ms. If the scheduler latency is greater than the 1.8ms value, the io_in( ) function will miss the
front end of the data stream. The bit rate processing capability scales with input clock rate.