HT46R46E datasheet(14/45 Pages) HOLTEK

14 / 45 page

HT46R46E/HT46C46E

Rev. 1.30

July 19, 2005

The registers

¢ states are summarized in the following table.

Reset

(Power On)

WDT Time-out

(Normal Operation)

RES Reset

(Normal Operation)

RES Reset

(HALT)

WDT Times-out

(HALT)*

TMR

xxxx xxxx

uuuu uuuu

TMRC

00-0 1000

uu-u uuuu

Program

Counter

000H

-xxx xxxx

-uuu uuuu

ACC

xxxx xxxx

uuuu uuuu

TBLP

xxxx xxxx

uuuu uuuu

TBLH

--xx xxxx

--uu uuuu

STATUS

--00 xxxx

--1u uuuu

--uu uuuu

--01 uuuu

--11 uuuu

INTC

-000 0000

-uuu uuuu

1111 1111

uuuu uuuu

PAC

1111 1111

uuuu uuuu

---- 1111

---- uuuu

PBC

---- 1111

---- uuuu

---- ---1

---- ---u

PDC

---- ---1

---- ---u

PWM

xxxx xxxx

uuuu uuuu

ADR

xxxx xxxx

uuuu uuuu

ADCR

0100 0000

uuuu uuuu

ACSR

1--- --00

u--- --uu

Note:

²*² stands for warm reset

²u² stands for unchanged

²x² stands for unknown

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 fINT/[2

´(256-N)].

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

timer/event counter. The TMRC is a timer/event counter

control register, which defines some options.

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 fINT clock. The

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 fINT.

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

²0²) it will start counting until the TMR returns to the orig-

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

HT46R46E Datasheet(PDF) 14 Page - Holtek Semiconductor Inc

HT46R46E Datasheet(HTML) 14 Page - Holtek Semiconductor Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

Datasheet Download

Link URL