HT46R48E Holtek Semiconductor, HT46R48E Datasheet - Page 14

• Manufacturer Part Number: HT46R48E
• Description: Cost-Effective A/D Type 8-Bit OTP MCU
• Manufacturer: Holtek Semiconductor

The registers states are summarized in the following table.
Note:
Timer/Event Counter
A timer/event counter (TMR) is implemented in the
microcontroller. The timer/event counter contains an
8-bit programmable count-up counter and the clock may
come from an external source or the system clock.
Using external clock input allows the user to count exter-
nal events, measure time internals or pulse widths, or
generate an accurate time base. While using the inter-
nal clock allows the user to generate an accurate time
base.
The timer/event counter can generate PFD signal by us-
ing external or internal clock and PFD frequency is de-
termine by the equation f
There are 2 registers related to the timer/event counter;
TMR ([0DH]), TMRC ([0EH]). Two physical registers are
mapped to TMR location; writing TMR makes the start-
ing value be placed in the timer/event counter preload
register and reading TMR retrieves the contents of the
timer/event counter. The TMRC is a timer/event counter
control register, which defines some options.
Rev. 1.10
TMR
TMRC
Program
Counter
MP
ACC
TBLP
TBLH
STATUS
INTC
PA
PAC
PB
PBC
PC
PCC
PD
PDC
PWM
ADRL
ADRH
ADCR
ACSR
Register
* stands for warm reset
u stands for unchanged
x stands for unknown
(Power On)
1111 1111
1111 1111
1111 1111
1111 1111
0100 0000
00-0 1000
-000 0000
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
-xxx xxxx
xxxx xxxx
--00 xxxx
--xx xxxx
1--- --00
---- --11
---- --11
---- ---1
---- ---1
x--- ----
Reset
000H
INT
/[2 (256-N)].
(Normal Operation)
WDT Time-out
uuuu uuuu
uuuu uuuu
1111 1111
1111 1111
1111 1111
1111 1111
0100 0000
00-0 1000
-uuu uuuu
-000 0000
xxxx xxxx
--uu uuuu
--1u uuuu
xxxx xxxx
xxxx xxxx
1--- --00
---- --11
---- --11
---- ---1
---- ---1
x--- ----
000H
14
(Normal Operation)
The TM0, TM1 bits define the operating mode. The
event count mode is used to count external events,
which means the clock source comes from an external
(TMR) pin. The timer mode functions as a normal timer
with the clock source coming from the f
pulse width measurement mode can be used to count the
high or low level duration of the external signal (TMR). The
counting is based on the f
In the event count or timer mode, once the timer/event
counter starts counting, it will count from the current con-
tents in the timer/event counter to FFH. Once overflow oc-
curs, the counter is reloaded from the timer/event counter
preload register and generates the interrupt request flag
(TF; bit 5 of INTC) at the same time.
In the pulse width measurement mode with the TON
and TE bits equal to one, once the TMR has received a
transient from low to high (or high to low if the TE bits is
inal level and resets the TON. The measured result will
remain in the timer/event counter even if the activated
transient occurs again. In other words, only one cycle
0 ) it will start counting until the TMR returns to the orig-
RES Reset
uuuu uuuu
uuuu uuuu
1111 1111
1111 1111
1111 1111
1111 1111
0100 0000
00-0 1000
-uuu uuuu
-000 0000
xxxx xxxx
--uu uuuu
--uu uuuu
xxxx xxxx
xxxx xxxx
1--- --00
---- --11
---- --11
---- ---1
---- ---1
x--- ----
000H
RES Reset
uuuu uuuu
uuuu uuuu
1111 1111
1111 1111
1111 1111
1111 1111
0100 0000
00-0 1000
-uuu uuuu
-000 0000
xxxx xxxx
--uu uuuu
--01 uuuu
xxxx xxxx
xxxx xxxx
1--- --00
---- --11
---- --11
(HALT)
---- ---1
---- ---1
x--- ----
000H
INT
.
WDT Times-out
HT46R48E
March 24, 2006
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uu-u uuuu
-uuu uuuu
--uu uuuu
--11 uuuu
-uuu uuuu
(HALT)*
u--- --uu
---- --uu
---- --uu
INT
---- ---u
---- ---u
u--- ----
000H
clock. The