upd6p9 Renesas Electronics Corporation., upd6p9 Datasheet - Page 19

• Manufacturer Part Number: upd6p9
• Description: 4-bit Single-chip Microcontroller For Infrared Remote Control Transmission
• Manufacturer: Renesas Electronics Corporation.

4.3 Carrier Output
4.3.1 Carrier output generator
periods (MOD1 and MOD0 respectively).
the respective modulo registers. Each of these widths can be set in a range of 250 ns to 64 µ s (@ f
are read and written using timer manipulation instructions.
Carrier signal
The carrier generator consists of a 9-bit counter and two modulo registers for setting the high- and low-level
Notes 1. Bit 9 of the modulo register for setting the low-level period (MOD0) is fixed to 0.
The carrier duty ratio and carrier frequency can be determined by setting the high- and low-level widths using
The system clock multiplied by 2 is used for the 9-bit counter input (8 MHz when f
The values of MOD0 and MOD1 can be calculated from the following expressions.
MOD0 = (2 × f
MOD1 = (2 × f
Caution Be sure to input values in range of 001H to 1FFH to MOD0 and MOD1.
Remark D: Carrier duty ratio (0 < D < 1)
MOV A, M00
MOV A, M01
MOV A, M10
MOV A, M11
2. t
9
f
T: Carrier cycle ( µ s)
: Flag that enables timer output (timer block) (see Figure 4-1 Timer Configuration)
X
: Input clock (MHz)
X
X
F/F
Figure 4-3. Configuration of Remote Controller Carrier Generator
× (1 – D) × T) – 1
× D × T) – 1
Clear
Match
CARY
t
9
MOV M00, A
MOV M01, A
MOV M10, A
MOV M11, A
Modulo register for setting the high-level period (MOD1)
M11
t
8
t
7
t
6
t
M1
5
t
M10
4
Data Sheet U15144EJ1V1DS
t
3
MOV M0, #data10
MOV M1, #data10
MOV M0, @R0
MOV M1, @R0
t
2
t
1
9-bit counter
Comparator
Selector
t
0
Modulo register for setting the low-level period (MOD0)
0
M01
t
8
t
7
t
6
t
5
M0
t
4
M00
t
3
t
X
2
= 4 MHz). MOD0 and MOD1
t
1
Note 1
2f
t
0
X
Multiplier
µ PD6P9
f
X
X
= 4 MHz).
t
f
9
X
Note 2
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