LCD Controller

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Issue date: 13 August, 1999

Syntek Semiconductor Co., Ltd.

STK55C324

But the pull-up resistor will be disabled if this pin is set as output.

1008 Volume control for sound channel 1. Write only.

Bit 7-1 : Volume for sound channel 1. $FF is the maximum volume. If bit 1 of $1013 is zero, then bit

1 will output to SOUND 1 pin.

1009 Volume control for sound channel 2. Write only.

Bit 7-1 : Volume for sound channel 2. $FF is the maximum volume. If bit 3 of $1013 is zero, then bit

1 will output to SOUND 2 pin.

100C Set port 1 bit interrupt function. Write only.

* An '1' in this register will set the interrupt function of the corresponding pin of port 1 to be enable.

That is, an interrupt will be generated if a low level is detected in the pin.

* If port 1 are used as key inputs, there are several interrupts will be generated during key pressing

or release. This is caused by key bounce. It is suggested to disable the port1 interrupt after port 1

interrupt is detected and enable the port 1 interrupt after key released. Or enable port 1 interrupt

before entering sleep or standby mode and disable port 1 interrupt after IC wakeup.

* The default values for each bit is zero.

100D Timer 1 data. Read & write.

* Before writing $100D, the program should select timer clock ($100E) first.

* After timer 1 been enabled, the timer will start to count down. When timer counts to zero, the timer

will count from the initial value and IRQ2 will happen.

* Valid values are from 1 to 255. Zero is prohibited.

* If CPU read this register, the value will be 1 to 255. Please note that the CPU will never read a

zero from timer.

* The time elapse = ($100D)/timer clock

100E Timer 1 clock select and contrast setting. Write only.

Bit 2-0 : = 000 System clock/2

= 001 System clock/4

= 010 System clock/8

= 011 System clock/16

= 100 System clock/32

= 101 System clock/64

= 110 System clock/128

= 111 System clock/256