MS51
Nov. 28, 2019
Page
49
of 491
Rev 1.00
MS51
32K
SE
RIES
TE
CHNICAL RE
F
EREN
CE MA
N
UAL
SP
– Stack Pointer
Register
SFR Address
Reset Value
SP
81H, All pages
0000_0111b
7
6
5
4
3
2
1
0
SP[7:0]
R/W
Bit
Name
Description
7:0
SP[7:0]
Stack pointer
The Stack Pointer stores the scratch-pad RAM address where the stack begins. It is incremented
before data is stored during PUSH or CALL instructions. Note that the default value of SP is 07H.
This causes the stack to begin at location 08H.