ORG 0

	MOV	R0,#30h
	MOV	R1,#40h
	MOV	R2,#4
	LCALL	IRAMtoIRAM


	MOV 	DPTR, #100h
	MOV	R0, #50h
	MOV	R2, #1h
   	LCALL 	IRAMtoXRAM
	SJMP	$

;--------------------------------------------------
; Returns:
;   R0 - read key
;--------------------------------------------------
read_key:
	PUSH 	ACC
	SETB 	P5.7
	MOV 	20H, P.7
	JB	20H.3, pressed_1
	JB	20H.2, pressed_2
	JB	20H.1, pressed_3
	JB	20H.0, pressed_A

	CLR 	P5.7
	SETB 	P5.6
	MOV 	20H, P.7
	JB	20H.3, pressed_4
	JB	20H.2, pressed_5
	JB	20H.1, pressed_6
	JB	20H.0, pressed_B

	CLR 	P5.6
	SETB 	P5.5
	MOV 	20H, P.7
	JB	20H.3, pressed_7
	JB	20H.2, pressed_8
	JB	20H.1, pressed_9
	JB	20H.0, pressed_C

	CLR 	P5.5
	MOV 	20H, P.7
	JB	20H.3, pressed_asterix
	JB	20H.2, pressed_0
	JB	20H.1, pressed_hash
	JB	20H.0, pressed_D
	JMP	pressed_none

pressed_1:
	MOV R0, '1'
	JMP key_read

pressed_2:
	MOV R0, '2'
	JMP key_read

pressed_3:
	MOV R0, '3'
	JMP key_read

pressed_A:
	MOV R0, 'A'
	JMP key_read

pressed_4:
	MOV R0, '4'
	JMP key_read

pressed_5:
	MOV R0, '5'
	JMP key_read

pressed_6:
	MOV R0, '6'
	JMP key_read

pressed_B:
	MOV R0, 'B'
	JMP key_read

pressed_7:
	MOV R0, '7'
	JMP key_read

pressed_8:
	MOV R0, '8'
	JMP key_read

pressed_9:
	MOV R0, '9'
	JMP key_read

pressed_C:
	MOV R0, 'C'
	JMP key_read

pressed_asterix:
	MOV R0, '*'
	JMP key_read

pressed_0:
	MOV R0, '0'
	JMP key_read

pressed_hash:
	MOV R0, '#'
	JMP key_read

pressed_D:
	MOV R0, 'D'
	JMP key_read

pressed_none:
	MOV R0, 'X'

key_read:
	POP ACC
	RET

;--------------------------------------------------
; R0 - source adress
; R1 - destination address
; R2 - size
;--------------------------------------------------
IRAMtoIRAM:
	MOV 	A, @R0
	MOV 	@R1, A
	INC		R0
	INC 	R1
	DJNZ	R2, IRAMtoIRAM
	RET



;--------------------------------------------------
; R0 - source adress
; DPTR - destination address
; R2 - size
;--------------------------------------------------
IRAMtoXRAM:
	MOV 	A, @R0
	MOVX 	@DPTR, A
	INC		R0
	INC 	DPTR
	DJNZ	R2, IRAMtoXRAM
	RET


	END