uptown47
Lifetime Supporting Member
Hi all,
I'm just looking at an S5 to S7 conversion.
The code contains some LIR/TIR instructions which, through this site and experience, I have part of an idea about. I just wondered if someone could clarify a few things.
Here's the code snippet....
Thanks for any help you can give on these questions.
Cheers![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I'm just looking at an S5 to S7 conversion.
The code contains some LIR/TIR instructions which, through this site and experience, I have part of an idea about. I just wondered if someone could clarify a few things.
Here's the code snippet....
Code:
L KH 7E28 // The CPU map shows that DB blocks are addressed between
// KH 7E00 and KH 7EFF. I originally thought that 7E28h must
// mean DB 40 (ie. 28h = 40) but, there isn't a DB 40. There is
// a DB 20 so I'm thinking it must mean that. Is that correct?
// and, if so, why?
LIR 0
T FW 170 // Are we taking DB20.DBW0 and putting it into FW 170 ?
// Or is taking DB20.DBB0 and just putting that into FW 170?
// Also, why do it this way? Why not just OPN DB20,
// Load DBW0 and then transfer it to FW 170 ??
L KH 7E2A
LIR 0
T FW 172
AN F 20.3
JC =M001
L FY 120
SLW 1
L FW 170
+F
T FW 174
L FW 164
L FW 174
TIR 1 // Anyone know what this is doing? i.e. Where/What is it transferring
// And what is the significance of the '1' after TIR/LIR instead of '0'
// Is this some sort of offset?
Thanks for any help you can give on these questions.
Cheers