upd17240 Renesas Electronics Corporation., upd17240 Datasheet - Page 51

• Manufacturer Part Number: upd17240
• Description: 4-bit Single-chip Microcontrollers For Small General-purpose Infrared Remote Control Transmitters
• Manufacturer: Renesas Electronics Corporation.

5.3
(NRZHTMM), and NRZ low-level timer modulo register (NRZLTMM). The high-level and low-level periods are set in
the corresponding modulo registers through the DBF to determine the carrier duty factor and carrier frequency.
bits 0 and 1) of the register file (this clock for carrier generation is Rf
therefore, the input clock is 2 MHz (f
is called NRZLTMM. Data is written to these registers by the PUT instruction. The contents in these register are read
by the GET instruction.
file. Be sure to clear this bit to 0 to output a carrier.
µ PD17246 is provided with a carrier generator for the remote controller.
The remote controller carrier generator consists of an 8-bit counter, NRZ high-level timer modulo register
As a clock input to the 8-bit counter, f
The NRZ high-level output timer modulo register is called NRZHTMM, and the NRZ low-level timer modulo register
Whether the REM pin outputs a carrier or a high level is selected by REMEN (address 12H, bit 1) of the register
NRZLTMM
NRZHTMM
Carrier Generator for Remote Controller
3
0
7
7
2
0
6
6
8-bit modulo register
8-bit modulo register
5
5
µ PD17240, 17241, 17242, 17243, 17244, 17245, 17246
REMCK1
1
4
4
X
3
3
/2), 4 MHz (f
REMCK0
X
/2, f
0
2
2
X
, or 2f
Data Sheet U15002EJ1V1DS
1
1
Note Rf
REMCK1
X
X
Address
RF: 13H
), or 8 MHz (2f
can be selected by using REMCK0 and REMCK1 (address 13H,
0
0
1
1
0
0
X
= 2f
REMCK0
Peripheral register: 03H
Peripheral register: 03H
X
can be selected only when f
0
1
0
1
After reset
Address
Address
X
0H
X
).
). When Rf
Rf
Rf
Rf
X
X
X
= f
= f
= 2f
Clock for carrier generation (Rf
X
X
/2 (when f
X
(when f
R/W
R/W
Note
X
(when f
is oscillated by a 4 MHz resonator,
X
After reset
Undefined
After reset
Undefined
= 4 MHz, Rfx = 4 MHz)
X
X
= 4 MHz, Rf
X
= 3.5 to 4.5 MHz.
= 4 MHz, Rf
X
R/W
R/W
R/W
R/W
= 2 MHz)
X
= 8 MHz)
X
)
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