1/ What will happen when a master performs 2 exclusive read with 2 different transaction ID to the sam an address location??
Example: Master0 (M0) issue 2 exclusive read with 2 different transaction ID (first is 00 and second is 01) to the sam an address location.
What Master or slave must do in this case??
2/ What will happen when a master performs a exclusive read to an address location,
and then have a transaction read (NOT exclusive read) to that address location??
Thank you for your help.
yasuhikokoumoto wrote: Hello Cao Phi, you are right. A master can have several unique IDs. An explanation which a master has a single ID would be a kind of convention. If a master has several outstanding capabilities, it can issue several IDs. However, if a master will issue a transaction to the same address, the ID will be the same because the transactions should be serialized. Therefore, it impossible to make your scenario of two exclusive read with different IDs. Best regards, Yasuhiko Koumoto.
yasuhikokoumoto wrote:
Hello Cao Phi,
you are right. A master can have several unique IDs. An explanation which a master has a single ID would be a kind of convention.
If a master has several outstanding capabilities, it can issue several IDs.
However, if a master will issue a transaction to the same address, the ID will be the same because the transactions should be serialized.
Therefore, it impossible to make your scenario of two exclusive read with different IDs.
Best regards,
Yasuhiko Koumoto.
Hello Yasuhiko Koumoto,
You told "Anyway, two successive exclusive reads would be illegal and the behavior would be implementation defined."
I don't understand "two successive exclusive reads would be illegal", that mean two exclusive reads (different address) would be illegal or two exclusive reads (same address) would be illegal??
How many exclusive read An master can issue in a transaction (with different address/same address; ID can different)??
** Cao Phi
'illegal' means unusual.
If an exclusive read has been issued by a master, an exclusive write should be followed.
This is the normal sequence.
However, the specification says two successive exclusive reads from the same master are possible.
In this case, an exclusive monitor in a slave updates the target address for the ID.
I don't know why the master should do such a thing.
Best regards.
yasuhikokoumoto wrote: Hello Cao Phi, 'illegal' means unusual. If an exclusive read has been issued by a master, an exclusive write should be followed. This is the normal sequence. However, the specification says two successive exclusive reads from the same master are possible. In this case, an exclusive monitor in a slave updates the target address for the ID. I don't know why the master should do such a thing. Best regards. Yasuhiko Koumoto.