HT46C62 Holtek Semiconductor, HT46C62 Datasheet - Page 19

• Manufacturer Part Number: HT46C62
• Description: A/D with LCD Type 8-Bit MCU
• Manufacturer: Holtek Semiconductor

on PD0/PD1/PD2 (if PD0/PD1/PD2 is operating in out-
put mode). The I/O functions of PD0/PD1/PD2 are as
shown.
It is recommended that unused or not bonded out I/O
lines should be set as output pins by software instruction
to avoid consuming power under input floating state.
The definitions of PFD control signal and PFD output
frequency are listed in the following table.
Note:
Rev. 1.60
Timer
Mode
OFF
OFF
ON
ON
PD0
PD1
PD2
I/O
²X² stands for unused
²U² stands for unknown
²M² is ²256² for PFD
²N² is preload value for timer/event counter
²f
counter
Preload
Timer
Value
TMR
(Normal)
Logical
X
X
N
N
Input
I/P
² is input clock frequency for timer/event
PA3 Data
Register
(Normal)
0
1
0
1
Logical
Output
O/P
PA3 Pad
State
PFD
U
0
0
Logical
(PWM)
Input
I/P
f
TMR
Frequency
/[2´(M-N)]
PFD
(PWM)
PWM0
PWM1
PWM2
X
X
X
O/P
Input/Output Ports
19
PWM
The microcontroller provides 3 channels (6+2)/(7+1)
(dependent on options) bits PWM output shared with
PD0/PD1/PD2. The PWM channels have their data reg-
isters denoted as PWM0 (1AH), PWM1 (1BH) and
PWM2 (1CH). The frequency source of the PWM coun-
ter comes from f
registers. The waveforms of PWM outputs are as
shown. Once the PD0/PD1/PD2 are selected as the
PWM outputs and the output function of PD0/PD1/PD2
are enabled (PDC.0/PDC.1/ PDC.2=²0²), writing ²1² to
PD0/PD1/PD2 data register will enable the PWM output
function and writing ²0² will force the PD0/PD1/PD2 to
stay at ²0².
A (6+2) bits mode PWM cycle is divided into four modu-
lation cycles (modulation cycle 0~modulation cycle 3).
Each modulation cycle has 64 PWM input clock period.
In a (6+2) bit PWM function, the contents of the PWM
register is divided into two groups. Group 1 of the PWM
register is denoted by DC which is the value of
PWM.7~PWM.2. The group 2 is denoted by AC which is
the value of PWM.1~PWM.0.
In a (6+2) bits mode PWM cycle, the duty cycle of each
modulation cycle is shown in the table.
Modulation cycle i
Parameter
(i=0~3)
SYS
. The PWM registers are three 8-bit
HT46R62/HT46C62
AC (0~3)
i<AC
i³AC
Duty Cycle
July 14, 2005
DC + 1
DC
64
64