PXD20RM Datasheet, PDF (1236/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

35.4.5 AHB Bus Register Memory Map Descriptions
This chapter contains definitions of registers in the AMBA address space.
35.4.5.1 AHB Bus Access Considerations
It has to be noted that all logic in the QuadSPI module implementing the AHB Bus access is related to read
the content of an external serial flash device. Therefore the following restrictions apply to the QuadSPI
module w.r.t. accesses to the AHB bus:
• Any write access is answered with the ERROR condition according to the AMBA AHB
Specification. No write occurs.
• Any AHB Command resulting in the assertion of the QSPI_SFMFR[ABCEF] or the
QSPI_SFMFR[ABMEF] flags is answered with the ERROR condition according to the
AMBA_AHB specification. The resulting AHB Command is ignored.
• AHB Bus access types fully supported are NONSEQ and BUSY.
• AHB access type SEQ is treated in the same way like NONSEQ. Refer to the AMBA AHB
Specification for further details.
35.4.5.2 Memory Mapped Serial Flash Data - Individual Flash Mode on Flash A
Starting with address 0x7000_0000 the content of the first external serial flash devices is mapped into the
address space of the device containing the QuadSPI module. Serial flash address byte address 0x0
corresponds to bus address 0x7000_0000 with increasing order. Refer to Table 35-23 below for the address
mapping. The byte ordering for 32 bit access is given in Table 35-28 and for 64 bit read access the byte
ordering is given in Table 35-32.
Table 35-23. Memory Mapped Individual Flash Mode - Flash A Address Scheme
Memory Mapped Address
32 Bit Access
0x7000_0000
0x7000_0004
...
0x77FF_FFF8
0x77FF_FFFC
Memory Mapped Address
64 Bit Access
0x7000_0000
...
0x77FF_FFF8
Serial Flash Byte Address
0x000_0000 - 0x000_0003
0x000_0004 - 0x000_0007
...
0x7FF_FFF8 - 0x7FF_FFFB
0x7FF_FFFC - 0x7FF_FFFF
The available address range depends from the size of the external serial flash device. Any access beyond
the size of the external serial flash provides undefined results.
For details concerning the read process refer to Section 35.5.3.3, Flash Read.
35.4.5.3 Memory Mapped Serial Flash Data - Individual Flash Mode on Flash B
Starting with address 0x7800_0000 the content of the first external serial flash devices is mapped into the
address space of the device containing the QuadSPI module. Serial flash address byte address 0x0
corresponds to bus address 0x7800_0000 with increasing order. Refer to Table 35-24 below for the address
35-26
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor