PCA84C922AP PHILIPS [NXP Semiconductors], PCA84C922AP Datasheet - Page 15

• Manufacturer Part Number: PCA84C922AP
• Description: Microcontrollers for universal infrared remote transmitter applications
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
Table 5 Hardware Control Register (address 03H)
Table 6 Description of the HMCTL bits
1997 Oct 22
handbook, full pagewidth
7 to 5
Microcontrollers for universal infrared
remote transmitter applications
BIT
4
3
2
1
0
7
WRES
Rint
PWM
LgP
HF
SYMBOL
ILOUT
6
ON-time
These three bits are reserved.
Reset Watchdog Timer. This is not a flip-flop in the register and can only be written to. If a logic 1
is written to this bit the Watchdog Timer is reset.
Reset interrupt. When Rint = 1; the interrupt flag that was set by the derivative logic is cleared.
The Hardware Modulator can only be restarted after the interrupt flag is cleared; this avoids a
second interrupt being generated before the first one has been serviced.
Pulse Width Modulation. When PWM = 1 and LgP = 0; the Pulse Counter Register is ignored
and a continuous pulse train is generated, this is shown in Fig.13.
Long Pulse. When LgP = 1; the contents of the OFF-time Register are ignored. A single pulse is
generated; its pulse width being determined as shown below.
If HF = 1; this pulse is modulated with a frequency
High Frequency. When HF = 1; the ON-time part of the generated pulse is modulated with a
frequency
ON-time = 2 (on-time register = 0)
Pulse width
start
pulse #1
1
4
OFF-time
f
=
osc
5
, this is shown as CASE 2 in Figs 11 and 12.
Contents of ON-time Register
Fig.10 Example of ILOUT pulse train.
pulse #2
WRES
4
OFF-time = 4 (off-time register = 2)
end
interrupt
pulse #3
15
DESCRIPTION
Rint
elapse time by software
3
+
2
1
4
f
osc
PCA84C922; PCA84C923
number of pulses
, this is shown in Fig.12.
PWM
2
number of pulses = 3
LgP
1
MBE345
Product specification
--------
f
osc
1
HF
0