![Freescale Semiconductor PXR4030 Скачать руководство пользователя страница 1289](http://html1.mh-extra.com/html/freescale-semiconductor/pxr4030/pxr4030_reference-manual_23306601289.webp)
External Bus Interface (EBI)
Freescale Semiconductor
30-27
PXR40 Microcontroller Reference Manual, Rev. 1
Figure 30-16. Single Beat 32-bit Write Cycle, Non-CS Access, Zero Wait States
30.4.2.4.3
Back-to-Back Accesses
Due to internal bus protocol, one dead cycle is necessary between back-to-back external bus accesses that
are not part of a set of small accesses (see
Section 30.4.2.6, Small Accesses (Small Port Size and Short
for small access timing). A dead cycle refers to a cycle between the D_TA of a previous
transfer and the D_TS of the next transfer.
NOTE
In some cases, CS remains asserted during this dead cycle, such as the cases
of back-to-back writes or read-after-write to the same chip-select. See
Besides this dead cycle, in most cases, back-to-back accesses on the external bus do not cause any change
in the timing from that shown in the previous diagrams, and the two transactions are independent of each
other. The only exceptions to this are listed below:
•
Back-to-back accesses where the first access ends with an externally-driven D_TA or D_TEA. In
these cases, an extra cycle is required between the end of the first access and the D_TS assertion
of the second access. See
Section 30.4.2.8, Termination Signals Protocol
for more details.
The following diagrams show a few examples of back-to-back accesses on the external bus.
D_ADD_DAT is valid
D_CLKOUT
D_ADD[9:30]
D_TS
D_TA (Input)
D_RD_WR
D_BDIP
CS[n]
D_ADD_DAT is valid
The EBI drives address and control signals an extra cycle because it uses a latched
version of the external D_TA (1 cycle delayed) to terminate the cycle.
*
*
D_ADD_DAT[0:31]
D_WE[0:3]
Содержание PXR4030
Страница 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Страница 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Страница 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Страница 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Страница 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 158: ...Power Management Controller PMC 5 26 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 182: ...Frequency Modulated Phase Locked Loop FMPLL 6 24 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 278: ...System Integration Unit SIU 7 96 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 280: ...System Information Module PXR40 Microcontroller Reference Manual Rev 1 8 2 Freescale Semiconductor...
Страница 300: ...Boot Assist Module BAM 9 20 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 346: ...Interrupts and Interrupt Controller INTC 10 46 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 352: ...General Purpose Static RAM SRAM 11 6 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 432: ...Core e200z7 Overview PXR40 Microcontroller Reference Manual Rev 1 13 44 Freescale Semiconductor...
Страница 460: ...Peripheral Bridge PBRIDGE 15 16 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 478: ...Memory Protection Unit MPU 16 18 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 496: ...Error Correction Status Module ECSM 17 18 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 524: ...Periodic Interrupt Timer PIT_RTI 20 12 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 740: ...FlexRay Communication Controller FLEXRAY 22 156 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 928: ...Deserial Serial Peripheral Interface DSPI 25 68 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 982: ...Enhanced Serial Communication Interface eSCI 26 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1114: ...Enhanced Queued Analog to Digital Converter EQADC 27 132 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
Страница 1168: ...Decimation Filter 28 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1262: ...Enhanced Time Processing Unit eTPU2 29 94 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1399: ...Nexus Development Interface NDI Freescale Semiconductor 31 83 PXR40 Microcontroller Reference Manual Rev 1...
Страница 1400: ...Nexus Development Interface NDI 31 84 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...