EM78P803A

8-bit Micro-controller

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* This specification are subject to be changed without notice.

12

2005/8/12

V1.3.3

R4 (RBSR: RAM bank, RAM selection for common registers R20 ~ R3F)

7

6

5

4

3

2

1

0

RB1

RB0

RSR5

RSR4

RSR3

RSR2

RSR1

RSR0

R/W-0

R/W-0

R/W-x

R/W-x

R/W-x

R/W-x

R/W-x

R/W-x

Bit 0 ~ Bit 5 (RSR0 ~ RSR5) : Indirect addressing for common registers R20 ~ R3F

RSR bits are used to select up to 32 registers (R20 to R3F) in the indirect addressing mode.

Bit 6 ~ Bit 7 (RB0 ~ RB1) : Bank selection bits for common registers R20 ~ R3F

These selection bits are used to determine which bank is activated among the 3 banks for 32 registers (R20 to

R3F). The bank 3 doesn’t exist and cannot access.

(RB1,RB0)

Bank # for R20 ~ R3F

00

Bank 0

01

Bank 1

10

Bank 2

11

N/A

R5 (P5IOD: PORT5 I/O data, Program ROM page selection)

7

6

5

4

3

2

1

0

P57

P56

P55

P54

PS3

PS2

PS1

PS0

R/W

R/W

R/W

R/W

R-0

R/W-0

R/W-0

R/W-0

Bit 0 ~ 3 (PS0 ~ PS3) : Page selection bits

They should be set before JMP or CALL instruction.

Page select bits

PS3

PS2

PS1

PS0

Program memory page (Address)

0

0

0

0

Page 0

0

0

0

1

Page 1

0

0

1

0

Page 2

0

0

1

1

Page 3

:

:

:

:

:

:

:

:

:

:

0

1

1

0

Page 6

0

1

1

1

Page 7

User can use PAGE instruction to change page and maintain program page by user. Otherwise, user can use

far jump (FJMP) or far call (FCALL) instructions to program user's code. EMC’s complier maintains the

program page. It will change user's program by inserting instructions within program.

Bit 3 is always 0 and can’t be set.

Bit 5 ~ 7 (P54 ~ P57) : 4-bit PORT5(4 ~ 7) I/O data register

R6 (P6IOD: PORT6 I/O data)

7

6

5

4

3

2

1

0

P67

P66

P65

P64

P63

P62

P61

P60

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

Bit 0 ~ Bit 7 (P60 ~ P67) : 8-bit PORT6(0~7) I/O data register

User can use IOC register to define input or output each bit.

R7 (P7IOD: PORT7 I/O data)

7

6

5

4

3

2

1

0

P77

P76

P75

P74

P73

P72

P71

P70

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

Bit 0 ~ Bit 7 (P70 ~ P77) : 8-bit PORT7(0~7) I/O data register