9.7.3 TOS

Contents of the stack pointed to by the STKPTR register. This is the value that will be loaded into the Program Counter upon a RETURN or RETFIE instruction.

Note: The individual bytes in this multibyte register can be accessed with the following register names:

TOSU: Accesses the upper byte TOS[20:16]
TOSH: Accesses the high byte TOS[15:8]
TOSL: Accesses the low byte TOS[7:0]

Name:	TOS
Address:	0x4FD

Top-of-Stack Register


Bit	23	22	21	20	19	18	17	16
				TOS[20:16]
Access				R/W	R/W	R/W	R/W	R/W
Reset				0	0	0	0	0


Bit	15	14	13	12	11	10	9	8
	TOS[15:8]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	TOS[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

Bits 20:0 – TOS[20:0] Top-of-Stack

The individual bytes in this multibyte register can be accessed with the following register names: TOSU: Accesses the upper byte TOS[20:16] TOSH: Accesses the high byte TOS[15:8] TOSL: Accesses the low byte TOS[7:0]