We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
Machine Cycle: Difference between revisions
From SnesLab
(→References: figure name) |
(more info on how clocked) |
||
| (9 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
A '''Machine Cycle''' is one tick of the [[5A22]]. | A '''Machine Cycle''' is one tick of the [[5A22]]. It may be configured to take 6, 8, or 12 [[master clock]] cycles. In the SNES scene, we call the 6:1 configuration [[fastROM]] and the 8:1 configuration [[slowROM]]. The 5A22 decides which configuration to use depending on the address that is on the 65c816's address bus, and clocks the '816 clock input accordingly. | ||
Multiplication takes about 8 machine cycles and division takes about 16.<sup>[3]</sup> | |||
[[File:master clock divider speeds.png]] | |||
=== See Also === | === See Also === | ||
* [[Internal Cycle]] | * [[Internal Cycle]] | ||
* [[ | * [[STP]] | ||
=== References === | === References === | ||
# last bullet point under 13.2 of [https://archive.org/details/SNESDevManual/book1/page/n78 page 2-13-1 of Book I] of the official Super Nintendo development manual | |||
# Figure 3-4-2 "Clear Timing" on [https://archive.org/details/SNESDevManual/book1/page/n161 page 3-4-1 of Book I], lbid. | |||
# 15.2 Absolute Multiplication/Division on [https://archive.org/details/SNESDevManual/book1/page/n81 page 2-15-1 on Book I], lbid. | |||
# https://ersanio.gitbook.io/assembly-for-the-snes/deep-dives/cycles | |||
[[Category:SNES Hardware]] | [[Category:SNES Hardware]] | ||
[[Category:Official Jargon]] | [[Category:Official Jargon]] | ||
[[Category:Inherited from 6502]] | |||
[[Category:Timing]] | |||
Latest revision as of 13:45, 21 October 2024
A Machine Cycle is one tick of the 5A22. It may be configured to take 6, 8, or 12 master clock cycles. In the SNES scene, we call the 6:1 configuration fastROM and the 8:1 configuration slowROM. The 5A22 decides which configuration to use depending on the address that is on the 65c816's address bus, and clocks the '816 clock input accordingly.
Multiplication takes about 8 machine cycles and division takes about 16.[3]
See Also
References
- last bullet point under 13.2 of page 2-13-1 of Book I of the official Super Nintendo development manual
- Figure 3-4-2 "Clear Timing" on page 3-4-1 of Book I, lbid.
- 15.2 Absolute Multiplication/Division on page 2-15-1 on Book I, lbid.
- https://ersanio.gitbook.io/assembly-for-the-snes/deep-dives/cycles