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G
Electrical Specifications
(Continued)
7.3.8
Serial Port (UART)
Figure 7-39. UART, Sharp-IR, SIR, and Consumer Remote Control Timing
Table 7-24. UART, Sharp-IR, SIR, and Consumer Remote Control Parameters
Symbol
Parameter
Min
Max
Unit
Comments
t
BT
Single Bit Time in UART and
Sharp-IR
t
BTN
- 25
1
1.
t
BTN
is the nominal bit time in UART, Sharp-IR, SIR and Consumer Remote Control modes. It is determined by the set-
ting of the Baud Generator Divisor registers.
t
CWN
is the nominal pulse width of the modulation signal for Sharp-IR and Consumer Remote Control modes. It is de-
termined by the MCPW field (bits [7:5]) of the IRTXMC register and the TXHSC bit (bit 2) of the RCCFG register.
t
CPN
is the nominal period of the modulation signal for Sharp-IR and Consumer Remote Control modes. It is determined
by the MCFR field (bits [4:0]) of the IRTXMC register and the TXHSC bit (bit 2) of the RCCFG register.
t
MMIN
and t
MMAX
define the time range within which the period of the incoming subcarrier signal has to fall in order for
the signal to be accepted by the receiver. These time values are determined by the contents of register IRRXDC and
the setting of the RXHSC bit (bit 5) of the RCCFG register.
t
BTN
+ 25
ns
Transmitter
t
BTN
- 2%
t
BTN
+ 2%
ns
Receiver
t
CMW
Modulation Signal Pulse
Width in Sharp-IR and
Consumer Remote
Control
t
CWN
- 25
2
2.
t
CWN
+ 25
ns
Transmitter
500
ns
Receiver
t
CMP
Modulation Signal Period in
Sharp-IR and Consumer
Remote Control
t
CPN
- 25
3
3.
t
CPN
+ 25
ns
Transmitter
t
MMIN 4
4.
t
MMAX
4
ns
Receiver
t
SPW
SIR Signal Pulse Width
(
3
/
16
) x t
BTN
- 15
1
(
3
/
16
) x t
BTN
+
15
1
ns
Transmitter, Variable
1.48
1.78
μs
Transmitter, Fixed
1
μs
Receiver
S
DRT
SIR Data Rate Tolerance
% of Nominal Data Rate
±
0.87%
Transmitter
±
2.0%
Receiver
t
SJT
SIR Leading Edge Jitter
% of Nominal Bit Duration
±
2.5%
Transmitter
±
6.5%
Receiver
t
BT
t
SPW
t
CMP
UART
Sharp IR
Consumer
Remote
Control
SIR
t
CMW