S2357 clock out

By Shinobi

Expert (128)

Shinobi's picture

21-07-2020, 05:42

Hi..

I found that clock in in my s2357 msx engine chip in an msx ax200 is 3.5MHz
Then by checking the clock out pin whicj is the pin that goes to cpu clock pin, it sometimes reads in hertz and sometimes in KHz and sometimes it reads 3.5MHz and the msx works.
In all cases when i took a line from s2357 clock in to cpu directly without taking it from clock out of msx enginr, the msx worked
Is s2357 defected?? The sound works ok..
Is it ok to get a direct line from s2357 clock in to z80 clock pin??

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By gdx

Prophet (3839)

gdx's picture

21-07-2020, 10:47

AX-200 uses the S3527. It not seem have clock pin.
https://www.msx.org/wiki/Yamaha_S3527

By Jipe

Paragon (1404)

Jipe's picture

21-07-2020, 12:58

it's the same schematic of CX5MII

clock in : pin 30 of S3527 via R353 100 ohms is making by pin 8 CPUCLK of V9938 IC317

clock out : pin 29 of S3527 via R354 100 ohms go to pin 6 Z80 IC329

https://archive.org/details/YamahaCX5MIIServiceManual

By gdx

Prophet (3839)

gdx's picture

21-07-2020, 15:15

ф IN and ф OUT, strange name for clock pins. I had only watched pinout.

By Grauw

Ascended (9398)

Grauw's picture

21-07-2020, 17:40

It’s not uncommon to use phi for clock.

By gdx

Prophet (3839)

gdx's picture

22-07-2020, 10:14

Anyway, considering what is in the S3527, it was obvious that there were these clock pins.

By Shinobi

Expert (128)

Shinobi's picture

24-07-2020, 19:37

Any reason that why clock out of msx engine is not giving correct clock frequency??
Clock in is good 3.5 mhz..i can short it with clock out...is it safe?