Chapter 5. INSTRUCTION
(14) TM n
Naming :
Status :
Test Memory Bit
Comparison results to status
Format :
Operand :
Function :
Bit address 0
M(X,Y,n)
n
3
1?
ST
1 when M(X,Y,n)=1, ST
0 when M(X,Y,n)=0
<Purpose>
A test is made to find if the selected memory bit is logic. 1
Status is set depending on the result.
(15) BR a
Naming :
Status :
Branch on status 1
Conditional depending on the status
Format :
Operand :
Function :
Branch address a (Addr)
When ST =1 , PA
When ST = 0, PC
PB, PC
PC + 1, ST
a(Addr)
1
Note : PC indicates the next address in a fixed sequence that
is actually pseudo-random count.
<Purpose>
For some programs, normal sequential program execution can
be change.
A branch is conditionally implemented depending on the status
of results obtained by executing the previous instruction.
<Comment>
• Branch instruction is always conditional depending on the
status.
a. If the status is reset (logic 0), a branch instruction is not
rightly executed but the next instruction of the sequence is
executed.
b. If the status is set (logic 1), a branch instruction is executed
as follows.
• Branch is available in two types - short and long. The former
is for addressing in the current page and the latter for
addressing in the other page. Which type of branch to exeute
is decided according to the PB register. To execute a long
branch, data of the PB register should in advance be modified
to a desired page address through the LPBI instruction.
5-8
HYNIX [ HYNIX SEMICONDUCTOR ]
