PC8374T Datasheet, PDF (40/48 Pages) National Semiconductor (TI) – SafeKeeper Desktop Trustedl/O

2.0 Device Characteristics (Continued)
2.4.8 Serial Port, Sharp-IR, SIR and Consumer Remote Control Timing
Symbol
Parameter
Conditions
Min¹
Max¹
Unit
t_BT
Single Bit Time in Serial Port and Sharp-IR _Transmitter
t_BTN − 25²
t_BTN + 25
ns
Receiver
t_BTN − 2%
t_BTN + 2%
ns
t_CMW
Modulation Signal Pulse Width in Sharp-IR
and Consumer Remote Control
Transmitter
Receiver
t_CWN − 25³
500
t_CWN + 25
ns
ns
t_CMP
Modulation Signal Period in Sharp-IR and
Consumer Remote Control
Transmitter
Receiver
t_CPN − 25⁴
t_MMIN5
t_CPN + 25
ns
t_MMAX5
ns
t_SPW SIR Signal Pulse Width
Transmitter,
Variable
(³/₁₆) x t_BTN − 15²
(³/₁₆) x t_BTN + 15²
ns
Transmitter,
1.48
Fixed
1.78
µs
Receiver
1
µs
S_DRT
SIR Data Rate Tolerance.
% of Nominal Data Rate.
Transmitter
Receiver
± 0.87%
± 2.0%
t_SJT
SIR Leading Edge Jitter.
% of Nominal Bit Duration.
Transmitter
Receiver
± 2.5%
± 6.5%
1. Not tested. Guaranteed by design.
2. t_BTN is the nominal bit time in Serial Port, Sharp-IR, SIR and Consumer Remote Control modes. It is deter-
mined by the setting of the Baud Generator Divisor registers.
3. t_CWN is the nominal pulse width of the modulation signal for Sharp-IR and Consumer Remote Control modes. It
is determined by MCPW field (bits 7-5) of IRTXMC register and TXHSC bit (bit 2) of RCCFG register.
4. t_CPN is the nominal period of the modulation signal for Sharp-IR and Consumer Remote Control modes. It is
determined by MCFR field (bits 4-0) of IRTXMC register and the TXHSC bit (bit 2) of RCCFG register.
5. 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 the
IRRXDC register and the setting of RXHSC bit (bit 5) of RCCFG register.
Serial Port
Sharp-IR
Consumer Remote Control
SIR
t_BT
t_CMW
t_CMP
t_SPW
www.national.com
40
Revision 1.1