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Crossbar Switch (XBS)
15-6
Freescale Semiconductor
Address: 0xFC00_4110 (XBS_PRS1)
0xFC00_4210 (XBS_PRS2)
0xFC00_4310 (XBS_PRS3)
0xFC00_4410 (XBS_PRS4)
0xFC00_4510 (XBS_PRS5)
0xFC00_4710 (XBS_PRS7)
Access: Supervisor read/write
31
30
29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
R
RO
0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
ARB
0 0
PCTL
0
PARK
W
Reset
0
0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
0 0 0
0 0 0 0 0
1
After this bit is set, only a hardware reset clears it.
Figure 15-3. XBS Control Registers Slave
n
(XBS_CRS
n
)
Table 15-4. XBS_CRS
n
Field Descriptions
Field
Description
31
RO
Read only. Forces both of the slave port’s registers (XBS_CRS
n
and XBS_PRS
n
) to be read-only. After set, only a
hardware reset clears it.
0 Both of the slave port’s registers are writeable.
1 Both of the slave port’s registers are read-only and cannot be written (attempted writes have no effect on the
registers and result in a bus error response).
30–9
Reserved, must be cleared.
8
ARB
Arbitration Mode. Selects the arbitration policy for the slave port.
0
Fixed priority
1
Round robin (rotating) priority
7–6
Reserved, must be cleared.
5–4
PCTL
Parking control. Determines the slave port’s parking control. The low-power park feature results in an overall power
savings if the slave port is not saturated; however, this forces an extra latency clock when any master tries to access
the slave port while not in use because it is not parked on any master.
00 When no master makes a request, the arbiter parks the slave port on the master port defined by the PARK bit
field.
01 When no master makes a request, the arbiter parks the slave port on the last master to be in control of the slave
port.
10 When no master makes a request, the slave port is not parked on a master and the arbiter drives all outputs to
a constant safe state.
11 Reserved.
3
Reserved, must be cleared.
2–0
PARK
Park. Determines which master port the current slave port parks on when no masters are actively making requests
and the PCTL bits are cleared.
000 Park on master port M0 (ColdFire Core)
001 Park on master port M1 (eDMA Controller)
010 Park on master port M2 (FEC0)
011 Park on master port M3 (FEC1)
100 Reserved
101 Park on master port M5 (PCI Controller)
110 Park on master port M6 (USB OTG)
111 Park on master port M7 (Serial Boot)
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...