
Memory Controller
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor
11-75
Figure 11-63. CS Signal Selection
11.6.4.1.2
Byte-Select Signals (B
xTx)
BRx[MS] of the accessed memory bank selects a UPM on the currently requested cycle. The selected UPM
affects only the assertion and negation of the appropriate BS signal; its timing as specified in the RAM
word. The BS signals are controlled by the port size of the accessed bank, the transfer size of the
transaction, and the address accessed.
Figure 11-64
shows how UPMs control BS signals.
Figure 11-64. BS Signal Selection
The uppermost byte select (BS0) indicates that D[0–7] contains valid data during a cycle. Likewise, BS1
indicates that D[8–15] contains valid data, BS2 indicates that D[16–23] contains valid data, and BS3
indicates that D[24–31] contains valid data during a cycle, and so forth. Note that for a refresh timer
request, all the BS signals are asserted/negated by the UPM.
UPMA/B/C
SDRAM
GPCM
MUX
BRx[MS]
CS3
CS4
CS5
CS6
CS7
CS8
Switch
Bank Selected
CS9
CS10
CS11
CS0
CS1
CS2
UPMA
MUX
MS/BS
BS0
BS1
BS2
BS3
Bank Selected
BRx[PS]
A[29–31]
TSIZ
Byte-Select
Logic
UPMB
UPMC
BS4
BS5
BS6
BS7
Содержание MPC8250
Страница 90: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 lxxxviii Freescale Semiconductor...
Страница 94: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 I 4 Freescale Semiconductor...
Страница 118: ...Overview MPC8260 PowerQUICC II Family Reference Manual Rev 2 1 24 Freescale Semiconductor...
Страница 236: ...Reset MPC8260 PowerQUICC II Family Reference Manual Rev 2 5 14 Freescale Semiconductor...
Страница 274: ...60x Signals MPC8260 PowerQUICC II Family Reference Manual Rev 2 7 18 Freescale Semiconductor...
Страница 540: ...IEEE 1149 1 Test Access Port MPC8260 PowerQUICC II Family Reference Manual Rev 2 13 8 Freescale Semiconductor...
Страница 548: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 IV 8 Freescale Semiconductor...
Страница 704: ...Serial Communications Controllers SCCs MPC8260 PowerQUICC II Family Reference Manual Rev 2 20 26 Freescale Semiconductor...
Страница 770: ...SCC BISYNC Mode MPC8260 PowerQUICC II Family Reference Manual Rev 2 23 20 Freescale Semiconductor...
Страница 808: ...SCC Ethernet Mode MPC8260 PowerQUICC II Family Reference Manual Rev 2 25 24 Freescale Semiconductor...
Страница 848: ...Serial Management Controllers SMCs MPC8260 PowerQUICC II Family Reference Manual Rev 2 27 36 Freescale Semiconductor...
Страница 972: ...ATM Controller and AAL0 AAL1 and AAL5 MPC8260 PowerQUICC II Family Reference Manual Rev 2 30 52 Freescale Semiconductor...
Страница 1062: ...ATM AAL1 Circuit Emulation Service MPC8260 PowerQUICC II Family Reference Manual Rev 2 31 46 Freescale Semiconductor...
Страница 1072: ...ATM AAL2 MPC8260 PowerQUICC II Family Reference Manual Rev 2 32 10 Freescale Semiconductor...
Страница 1122: ...Inverse Multiplexing for ATM IMA MPC8260 PowerQUICC II Family Reference Manual Rev 2 33 20 Freescale Semiconductor...
Страница 1178: ...Inverse Multiplexing for ATM IMA MPC8260 PowerQUICC II Family Reference Manual Rev 2 33 76 Freescale Semiconductor...
Страница 1224: ...Fast Ethernet Controller MPC8260 PowerQUICC II Family Reference Manual Rev 2 35 28 Freescale Semiconductor...
Страница 1242: ...FCC HDLC Controller MPC8260 PowerQUICC II Family Reference Manual Rev 2 36 18 Freescale Semiconductor...
Страница 1302: ...Register Quick Reference Guide MPC8260 PowerQUICC II Family Reference Manual Rev 2 A 4 Freescale Semiconductor...
Страница 1318: ...Reference Manual Rev 1 Errata MPC8260 PowerQUICC II Family Reference Manual Rev 2 B 16 Freescale Semiconductor...
Страница 1356: ...MPC8260 PowerQUICC II Family Reference Manual Rev 2 Index 28 Freescale Semiconductor U U Index...