PIC17C7XX_13 Datasheet, PDF (262/306 Pages) Microchip Technology – High-Performance 8-bit CMOS EPROM Microcontrollers with 10-bit A/D

PIC17C7XX
FIGURE 20-21:
USART ASYNCHRONOUS MODE START BIT DETECT
RX
(RX/DT pin)
x16 CLK
121A
START bit
Q2, Q4 CLK
120A
123A
TABLE 20-16: USART ASYNCHRONOUS MODE START BIT DETECT REQUIREMENTS
Param
No.
Sym
Characteristic
Min
120A TdtL2ckH Time to ensure that the RX pin is sampled low
—
121A TdtRF
Data rise time and fall time
Receive
—
Transmit
—
123A TckH2bckL Time from RX pin sampled low to first rising edge —
of x16 clock
Note 1: Schmitt trigger will determine logic level.
Typ
Max
Unit
s
—
TCY
ns
— (Note 1) ns
—
40
ns
—
TCY
ns
Conditions
FIGURE 20-22:
RX
(RX/DT pin)
Baud CLK
x16 CLK
USART ASYNCHRONOUS RECEIVE SAMPLING WAVEFORM
START bit
Bit0
Baud CLK for all but START bit
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 2 3
125A
126A
Samples
TABLE 20-17: USART ASYNCHRONOUS RECEIVE SAMPLING REQUIREMENTS
Param
No.
125A
126A
Sym
Characteristic
Min
Typ
Max
Unit
s
TdtL2ckH Setup time of RX pin to first data sampled TCY
—
—
ns
TdtL2ckH Hold time of RX pin from last data sam-
pled
TCY
—
—
ns
Conditions
DS30289C-page 262
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