Intel® PXA26x Processor Family Developer’s Manual 18-1
Internal Flash 18
This chapter describes the flash interface for the Intel® PXA26x Processor Family. The PXA26x
processor family has three devices that contain internal Intel Stra taFlash® memory:
PXA261 processor – 128megabit x 16 Intel StrataFlash® memory
PXA262 processor – 256megabit x 16 Intel StrataFlash® memory
PXA263 processor – 256 megabit x 32 Intel StrataFlash® memory
For the best performance, configure one of t he PX A26x proces sor fami ly dev ices ( in the li st ab ove )
in synchronous mode.
Note: This section describes the synchronous Intel StrataFlas h® memory. All references to Intel
StrataFlash® memory is to the synchronous (K3) version.

18.1 Initialization

During boot-up, the Intel StrataFlash® memory exits reset in asynchronous mode. Configure the
PXA26x processor family BOOT _S EL pins as asynchronous flash me mo ry for the correct bus
width. After boot-up, configure the memory controller in synchronous mode.

18.1.1 Intel StrataFlash® Memory Reset Configuration

Connect nRESET_OUT to nRST_F, for har dware reset, watchdog reset, and sleep mode to work
properly. GPIO reset does not work because the contents of the memory con troller Synchronous
Static Memory Configuration Register (SXCNFG) are not reset, but the flash would be reset to
asynchronous mode. If GPIO reset operation is required, a state machin e is necessary between
nRESET, nRESET_OUT, GPIO[1], and nRST_F to guar antee that nRST_F is asserted during
hardware reset, watchdog reset, and sleep mode, and not asserted during GPIO reset. Figure18-1
shows the required logic. GPIO_a is an unused G PIO t hat is dri ven low b y so ftwar e du ring the bo ot
sequence and left high during normal operation. After this is completed, then enable GPIO reset.
Figure 18-1. Flash Memory Reset Using State Machine
nS
nR
GPIO[1]
GPIO_a
Q
nRESET_OUT nRESET
nRST_F
PXA26x