Introduction

1.2.6Memory

The volatile memory system includes SSRAM and SDRAM memory. You can expand this memory by installing external static or dynamic memory expansion boards.

The nonvolatile memory system consists of 128MB of 32-bit flash. The flash is managed by the static memory controller in the ARM926EJ-S PXP Development Chip. You can expand the flash memory by installing an external static memory expansion board. See Appendix E Memory Expansion Boards.

1.2.7Clock generators

The PB926EJ-S contains the following clock sources:

crystal oscillators (these are the reference frequencies for the Real Time Clock, USB, AACI, Ethernet, and programmable oscillators)

five programmable ICS307 clock sources. Two of these are used as the reference for the CPU system clock in the ARM926EJ-S PXP Development Chip and the CLCD controller clock. The other three programmable clocks can be used as external reference clocks for the AHB buses.

if fitted, the PCI backplane or RealView Logic Tiles. The external clocks can be selected as the reference clocks for the PB926EJ-S.

See Clock architecture on page 3-35.

1.2.8Debug and test interfaces

The JTAG connector enables JTAG hardware debugging equipment, such as Multi-ICE or RealView ICE, to be connected to the PB926EJ-S. The JTAG signals can also be controlled by the on-board USB debug port controller. See JTAG and USB debug port support on page 3-96.

AMictor connector on the PB926EJ-S enables monitoring of the ARM926EJ-S PXP Development Chip Embedded Trace Macrocell (ETM9) signals by a Trace Port Analyzer (TPA). The trace port is medium trace size (16-bit packet). See Trace connector pinout on page A-37 for connection information.

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ARM DUI 0224I

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ARM ARM DUI 0224I manual Memory, Clock generators, Debug and test interfaces