Ok, I didn't understand.
I will read
Naomi Dualbiosmod
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OldFoo
Ok I read what you posted.
I understand that we can modify the state of the chip to read or not informations. But what I don't understand very well is : Output Enable. When this signal is low the chip will put it's data on the bus when read. It means that the chip can't be read ?
Which is the difference with Chip enable mode
I am reading an documentation in french. I understand that there is three bus on a chip :
Adress bus
Data bus
Control bus.
What I have do to do to connect two chips together, is to connect control bus of each chip to a switch in order to change the state of the two chips in the same time.
I understand that we can modify the state of the chip to read or not informations. But what I don't understand very well is : Output Enable. When this signal is low the chip will put it's data on the bus when read. It means that the chip can't be read ?
Which is the difference with Chip enable mode
I am reading an documentation in french. I understand that there is three bus on a chip :
Adress bus
Data bus
Control bus.
What I have do to do to connect two chips together, is to connect control bus of each chip to a switch in order to change the state of the two chips in the same time.
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OldFoo
BINGO!
You got it.
First, you need to check the BIOS socket on the NAOMI board. Check the OE* and the CE* pins to see if one is connected to ground. If it is then you don't have to worry with switching it.
The one line that does need to be switched can be done with a simple toggle switch.
Simply tie the control lines high through resistors so that if they aren't connected into circuit they are kept at a logic "high" so they aren't enabled by accident.
The resistors aren't low enough in value to cause them to be stuck high when in circuit which is the balance you are trying to achieve.
BUT, you must figure out which control line to do this to. One will probably be tied to ground and the other one is the one you want to focus on.
The rest of the pins all connect together. The center post of the SPDT switch connects to the pin on the socket that the control line (the one that wasn't grounded) originally plugged into.
RJ
PS: Do NOT flip the switch with the power on. You'll crash the NAOMI and will have to power cycle it to recover.
You got it.
First, you need to check the BIOS socket on the NAOMI board. Check the OE* and the CE* pins to see if one is connected to ground. If it is then you don't have to worry with switching it.
The one line that does need to be switched can be done with a simple toggle switch.
Code: Select all
+5v Control Line +5v
| | |
/ | /
\ | \
/ 330 | / 330
\ ohm | \ ohm
| | |
| | |
| / |
chip 1 ------------------o o--------------- chip 2
SPDT Switch
Simply tie the control lines high through resistors so that if they aren't connected into circuit they are kept at a logic "high" so they aren't enabled by accident.
The resistors aren't low enough in value to cause them to be stuck high when in circuit which is the balance you are trying to achieve.
BUT, you must figure out which control line to do this to. One will probably be tied to ground and the other one is the one you want to focus on.
The rest of the pins all connect together. The center post of the SPDT switch connects to the pin on the socket that the control line (the one that wasn't grounded) originally plugged into.
RJ
PS: Do NOT flip the switch with the power on. You'll crash the NAOMI and will have to power cycle it to recover.
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OldFoo