MPC563XM Reference Manual, Rev. 1
200
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
8.6.2.5
Error Response Terminated Accesses
A master access will be responded to with an error if the
hsel
input of the XBAR is asserted and the transfer
type is non IDLE and the access decodes to a location not occupied by a slave port. This is the only time
the XBAR will respond with an error response. All other error responses received by the master are the
result of error responses on the slave ports being passed through the XBAR.
Please reference
Section 8.8.1.1, “Port Presence,”
and
Section 8.8.2, “Address Map,”
for information on
locations that are not occupied by a slave port.
8.6.3
Slave Ports
The goal of the XBAR with respect to the slave ports is to keep them 100% saturated when masters are
actively making requests. In order to do this the XBAR must not insert any bubbles onto the slave bus
unless absolutely necessary.
There is only one instance when the XBAR will force a bubble onto the slave bus when a master is actively
making a request. This occurs when a higher priority master has control of the slave port and is running
single clock (zero wait state) accesses while a lower priority master is stalled waiting for control of the
slave port. When the higher priority master either leaves the slave port or runs an IDLE cycle to the slave
port the XBAR will take control of the slave bus and run a single IDLE cycle before giving the slave port
to the lower priority master that was waiting for control of the slave port.
The only other times the XBAR will have control of the slave port is when the XBAR is halting or when
no masters are making access requests to the slave port and the XBAR is forced to either park the slave
port on a specific master or put the slave port into low power park mode.
In most instances when the XBAR has control of the slave port it will indicate IDLE for the transfer type,
negate all control signals and indicate ownership of the slave bus via the
hmaster
encoding of 4’b0000.
One exception to this rule is when a master running locked cycles has left the slave port but continues to
run locked cycles. In this case the XBAR will control the slave port and will indicate IDLE for the transfer
type but it will not affect any other signals.
NOTE
When a master runs a locked cycle through the XBAR, the master will be
guaranteed ownership of all slave ports it accesses while running locked
cycles for one cycle beyond when the master finishes running locked cycles.
Содержание MPC5632M
Страница 22: ...MPC563XM Reference Manual Rev 1 22 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 62: ...MPC563XM Reference Manual Rev 1 62 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 92: ...MPC563XM Reference Manual Rev 1 92 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 168: ...MPC563XM Reference Manual Rev 1 168 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 242: ...MPC563XM Reference Manual Rev 1 242 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 302: ...MPC563XM Reference Manual Rev 1 302 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 410: ...MPC563XM Reference Manual Rev 1 410 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 440: ...MPC563XM Reference Manual Rev 1 440 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 464: ...MPC563XM Reference Manual Rev 1 464 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 554: ...MPC563XM Reference Manual Rev 1 554 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 590: ...MPC563XM Reference Manual Rev 1 590 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 622: ...MPC563XM Reference Manual Rev 1 622 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 716: ...MPC563XM Reference Manual Rev 1 716 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1114: ...MPC563XM Reference Manual Rev 1 1114 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1144: ...MPC563XM Reference Manual Rev 1 1144 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1266: ...MPC563XM Reference Manual Rev 1 1266 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1316: ...MPC563XM Reference Manual Rev 1 1316 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1348: ...MPC563XM Reference Manual Rev 1 1348 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1362: ...MPC563XM Reference Manual Rev 1 1362 Freescale Semiconductor Preliminary Subject to Change Without Notice ...
Страница 1382: ...MPC563XM Reference Manual Rev 1 1382 Freescale Semiconductor Preliminary Subject to Change Without Notice ...