Memory Controller
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Freescale Semiconductor
15-41
15.6.4.2
Chip-Select Signals (CST
x)
If BRx[MS] of the accessed bank selects a UPM on the currently requested cycle the UPM manipulates
the CS signal for that bank with timing as specified in the UPM RAM word. The selected UPM affects
only assertion and negation of the appropriate CSx signal. The state of the selected CSx signal of the
corresponding bank depends on the value of each CSTn bit.
Figure 15-40
and the timing diagrams in
Figure 15-36
and
Figure 15-37
shows how UPMs control CS
signals.
26–27
AMX
Address multiplexing. Determines the source of A[0:31] at the falling edge of GCLK1_50.
00 A[0:31] is the non-multiplexed address. For example, column address.
01 Reserved.
10 A[0:31] is the address requested by the internal master multiplexed according to M
xMR[AMx].
For example, row address.
11 A[0:31]
is the contents of MAR. Used for example, during SDRAM mode initialization.
28
NA
Next address. Determines when the address is incremented during a burst access.
0 The address increment function is disabled
1 The address is incremented in the next cycle. With the BR
x[PS], the increment value of A[28:31]
and/or BADDR[28:30] at the falling edge of GCLK1_50 is as follows
If the accessed bank has a 32-bit port size, the value is incremented by 4.
If the accessed bank has a 16-bit port size, the value is incremented by 2.
If the accessed bank has an 8-bit port size, the value is incremented by 1.
Note: The value of NA is relevant only when the UPM serves a burst-read or burst-write request.
NA is reserved under other patterns.
29
UTA
UPM transfer acknowledge. Controls the state of TA sampled by the external bus interface in the
current memory cycle. TA is output at the rising edge of GCLK2_50.
0 TA is driven low on the rising edge of GCLK2_50. The bus master samples it low in the next clock
cycle.
1 TA is driven high on the rising edge of GCLK2_50.
30
TODT
Turn-on disable timer. Controls the disable timer mechanism. This bit has meaning only in RAM
words for which UTA = 0; otherwise it is a don’t care.
0 The disable timer is turned off.
1 The disable timer for the current bank is activated preventing a new access to the same bank
(when controlled by the UPMs) until the disable timer expires. For example, precharge time.
31
LAST
Last. If this bit is set, it is the last RAM word in the program.
0 The UPM continues executing RAM words.
1 The service to the UPM request is done.
Table 15-14. RAM Word Bit Settings (continued)
Bit
Name
Description
Содержание PowerQUICC MPC870
Страница 1: ...MPC885 PowerQUICC Family Reference Manual Supports MPC885 MPC880 MPC875 MPC870 MPC885RM Rev 2 04 2006 ...
Страница 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
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 ...
Страница 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
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 ...
Страница 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Страница 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
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 ...