Instruction and Data Caches
MPC885 PowerQUICC Family Reference Manual, Rev. 2
7-12
Freescale Semiconductor
Table 7-7
describes the bits of the DC_CST register.
Table 7-7. Data Cache Control and Status Register—DC_CST
Bits
Name
Description
0
DEN
Data cache enable status
0 The data cache is disabled.
1 The data cache is enabled.
Note:
This is a read-only bit. Any attempt to write to it is ignored. This bit is programmed by issuing
the appropriate command in DC_CST[CMD].
1
DFWT
Data cache forced write-through
0 The write-through behavior of the data cache is determined by the write-through memory/cache
access attribute (the W bit) in the MMU.
1 Writes to the data cache are forced to write through to memory.
Note:
This is a read-only bit. Any attempt to write to it is ignored. This bit is programmed by issuing
the appropriate command in DC_CST[CMD].
2
LES
Little-endian swap
0 Used for big-endian (BE) and modified little-endian (MOD-LE) modes. No modifications to the
address or byte lanes are performed.
1 Used for true little-endian (TLE) mode. A 2-bit munge is performed on the physical address before
accessing the internal U-bus. Also, for accesses originating from the MPC8xx core, the SIU
unmunges the address and swaps the bytes of data within each word at the external bus/internal
U-bus boundary.
See
Appendix A, “Byte Ordering,”
for more information about MPC885 byte ordering. Note that this
is a read-only bit. Any attempt to write to it is ignored. This bit is programmed by issuing the
appropriate command in DC_CST[CMD].
3
Reserved
4–7
CMD
Data cache command
0000 Reserved
0001 Set forced write-through bit
0010 Cache enable
0011 Clear forced write-through bit
0100 Cache disable
0101 Set true little-endian swap bit
0110 load-and-lock cache block
0111 Clear little-endian swap bit
1000 Unlock cache block
1001 Reserved
1010 Unlock all
1011 Reserved
1100 Invalidate all
1101 Reserved
1110 Flush cache block
1111 Reserved
Note:
Reading these bits always returns 0b0000
8–9
Reserved
10
CCER1 Data cache error type 1. Copyback error during
dcbf
or
dcbst
instruction execution or during
DC_CST flush cache block command. A machine check exception is generated when this bit is set.
0 No error detected
1 Error detected
Note that this is a read-only, sticky bit, set only by the MPC885 when an error is detected. Reading
this bit clears it.
Содержание PowerQUICC MPC870
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Страница 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Страница 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Страница 192: ...MPC885 Instruction Set MPC885 PowerQUICC Family Reference Manual Rev 2 5 22 Freescale Semiconductor ...
Страница 242: ...Instruction and Data Caches MPC885 PowerQUICC Family Reference Manual Rev 2 7 30 Freescale Semiconductor ...
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Страница 416: ...External Bus Interface MPC885 PowerQUICC Family Reference Manual Rev 2 13 42 Freescale Semiconductor ...
Страница 440: ...Clocks and Power Control MPC885 PowerQUICC Family Reference Manual Rev 2 14 24 Freescale Semiconductor ...
Страница 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Страница 606: ...SDMA Channels and IDMA Emulation MPC885 PowerQUICC Family Reference Manual Rev 2 19 20 Freescale Semiconductor ...
Страница 738: ...SCC Asynchronous HDLC Mode and IrDA MPC885 PowerQUICC Family Reference Manual Rev 2 25 16 Freescale Semiconductor ...
Страница 780: ...SCC Ethernet Mode MPC885 PowerQUICC Family Reference Manual Rev 2 27 24 Freescale Semiconductor ...
Страница 794: ...SCC Transparent Mode MPC885 PowerQUICC Family Reference Manual Rev 2 28 14 Freescale Semiconductor ...
Страница 848: ...Serial Peripheral Interface SPI MPC885 PowerQUICC Family Reference Manual Rev 2 30 18 Freescale Semiconductor ...
Страница 882: ...Universal Serial Bus USB MPC885 PowerQUICC Family Reference Manual Rev 2 31 34 Freescale Semiconductor ...
Страница 944: ...Parallel I O Ports MPC885 PowerQUICC Family Reference Manual Rev 2 34 26 Freescale Semiconductor ...
Страница 956: ...CPM Interrupt Controller MPC885 PowerQUICC Family Reference Manual Rev 2 35 12 Freescale Semiconductor ...
Страница 1004: ...Buffer Descriptors and Connection Tables MPC885 PowerQUICC Family Reference Manual Rev 2 37 30 Freescale Semiconductor ...
Страница 1022: ...ATM Parameter RAM MPC885 PowerQUICC Family Reference Manual Rev 2 38 18 Freescale Semiconductor ...
Страница 1068: ...ATM Pace Control MPC885 PowerQUICC Family Reference Manual Rev 2 40 22 Freescale Semiconductor ...
Страница 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Страница 1120: ...AAL2 Implementation MPC885 PowerQUICC Family Reference Manual Rev 2 44 30 Freescale Semiconductor ...
Страница 1162: ...Fast Ethernet Controller FEC MPC885 PowerQUICC Family Reference Manual Rev 2 45 40 Freescale Semiconductor ...
Страница 1172: ...SEC Lite Overview MPC885 PowerQUICC Family Reference Manual Rev 2 46 8 Freescale Semiconductor ...
Страница 1176: ...SEC Lite Address Map MPC885 PowerQUICC Family Reference Manual Rev 2 47 4 Freescale Semiconductor ...
Страница 1214: ...SEC Lite Execution Units MPC885 PowerQUICC Family Reference Manual Rev 2 48 38 Freescale Semiconductor ...
Страница 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Страница 1313: ...MPC885 PowerQUICC Family Reference Manual Rev 2 Freescale Semiconductor B 1 Appendix B Serial Communications Performance TBD ...
Страница 1314: ...Serial Communications Performance MPC885 PowerQUICC Family Reference Manual Rev 2 B 2 Freescale Semiconductor ...
Страница 1320: ...Register Quick Reference Guide MPC885 PowerQUICC Family Reference Manual Rev 2 C 6 Freescale Semiconductor ...
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Страница 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Страница 1384: ...Serial ATM Scrambling Reception and SI Programming MPC885 PowerQUICC Family Reference Manual Rev 2 H 6 Freescale Semiconductor ...
Страница 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...