HMS87C1808B Datasheet, PDF (54/99 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS

HMS87C1X04B/08B/16B
12.5 16-bit Capture Mode
16-bit capture mode is the same as 8-bit capture, except that the
Timer register is being run will 16 bits.
The clock source of the Timer 0 is selected either internal or ex-
ternal clock by bit T0CK2, T0CK1 and T0CK0.
In 16-bit mode, the bits T1CK1,T1CK0 and 16BIT of TM1
should be set to “1” respectively.
TM0
TM1
EC0
fxin
INT0
ADDRESS : D0H
-
-
CAP0 T0CK2 T0CK1 T0CK0 T0CN T0ST
RESET VALUE : --00_0000
-
-
1
X
X
X
X
X
POL
16BIT PWME CAP1 T1CK1 T1CK0 T1CN
T1ST
ADDRESS : D2H
RESET VALUE : 0000_0000
X
1
0
X
1
1
X
X
T0CK[2:0]
Edge Detector
X: The value “0” or “1” corresponding your operation.
T0ST
0 : Stop
1 : Clear and Start
÷2
÷4
÷8
÷ 32
÷ 128
÷ 512
÷ 2048
MUX
1
T0CN
CAPTURE
T0 + T1 (16-bit)
CLEAR
COMPARATOR
CDR1 CDR0 TDR1 TDR0
(8-bit) (8-bit) (8-bit) (8-bit)
T0IF
INT0IF
TIMER 0
INTERRUPT
INT 0
INTERRUPT
IEDS[1:0]
Figure 12-9 16-bit Capture Mode
12.6 PWM Mode
The HMS87C1X04B/08B/16B has a two high speed PWM
(Pulse Width Modulation) functions which shared with Timer1
(Timer 3). In this document, it will be explained only PWM0.
In PWM mode, pin RB4/COMP0/PWM0 outputs up to a 10-bit
resolution PWM output. This pin should be configure as a PWM
output by setting “1” bit PWM0O in RBFUNC register. (PWM1
output by setting “1” bit PWM1O in RBFUNC)
The period of the PWM output is determined by the T1PPR
(PWM0 Period Register) and PWM0HR[3:2] (bit3,2 of PWM0
High Register) and the duty of the PWM output is determined by
the T1PDR (PWM0 Duty Register) and PWM0HR[1:0] (bit1,0 of
PWM0 High Register).
The user writes the lower 8-bit period value to the T1PPR and the
higher 2-bit period value to the PWM0HR[3:2]. And writes duty
value to the T1PDR and the PWM0HR[1:0] same way.
The T1PDR is configure as a double buffering for glitchless
PWM output. In Figure 12-10 , the duty data is transferred from
the master to the slave when the period data matched to the count-
ed value. (i.e. at the beginning of next duty cycle)
PWM Period = [PWM0HR[3:2]T1PPR] X Source Clock
PWM Duty = [PWM0HR[1:0]T1PDR] X Source Clock
The relation of frequency and resolution is in inverse proportion.
Table 12-1 shows the relation of PWM frequency vs. resolution.
50
SEP. 2004 Ver 1.03