EM73880 datasheet(20/40 Pages) EMC

20 / 40 page

* This specification are subject to be changed without notice.

EM73880

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

11.30.2001

Preliminary

Interrupt controller:

IL0-IL5

: Interrupt latch . Hold all interrupt requests from all interrupt sources. ILr can not be

set by program, but can be reset by program or system reset, so IL only can decide

which interrupt source can be accepted.

MASK0-MASK3

: Except INT0 ,MASK register can promit or inhibit all interrupt sources.

: Enable interrupt Flip-Flop can promit or inhibit all interrupt sources, when inter-

rupt happened, EI is cleared to "0" automatically, after RTI instruction happened,

EI will be set to "1" again .

Priority checker: Check interrupt priority when multiple interrupts happened.

INTERRUPT FUNCTION

The procedure of interrupt operation:

1. Push PC and all flags to stack.

2. Set interrupt entry address into PC.

3. Set SF= 1.

4. Clear EI to inhibit other interrupts happened.

5. Clear the IL for which interrupt source has already be accepted.

6. To excute interrupt subroutine from the interrupt entry address.

7. CPU accept RTI, restore PC and flags from stack . Set EI to accept other interrupt requests.

PROGRAM EXAMPLE: To enable interrupt of "INT0, TRGA"

LDIA #1100B;

EXAE; set mask register "1100B"

EICIL 111111B ; enable interrupt F.F.

SPEECH SYNTHESIZER OPERATES PROCEDURE

1. Send the speech start address to the address latch by writing P6 four times.

2. Choose the sampling rate, enable the speech synthesizer by writing P5.

3. The ROM address counters send the ROM address A6 .. A18 to the speech ROM.

4. ACT is the speech acknowledge signal. When the speech synthesizer has voice output. ACT is high .

When ACT is changed from high to low, the speech synthesizer can generate the speech ending

interrupt SPI. The ACT signal can be read from P5.3.

EM73880 Datasheet(PDF) 20 Page - ELAN Microelectronics Corp