9.3.5. ETB RAM Write Pointer Register, RWP, 0x018

The RAM Write Pointer Register sets the write pointer used to write entries from the CoreSight bus into Trace RAM. During trace capture the pointer increments when the DataValid flag is asserted by the Formatter. When this register increments from its maximum value back to zero, the Full flag is set.

This register can also be written to over APB to set the pointer for write accesses carried out through the APB interface.

This register must not be written to when trace capture is enabled (FtStopped=0, TraceCaptEn=1). If access is attempted, the register is not updated. The register can also be read to determine the current memory location being referenced.

It is recommended that addresses are 128-bit aligned when the formatter is used in normal or continuous modes.

Table 9.9 shows the ETB RAM Write Pointer Register bit assignments.

Table 9.9. ETB RAM Write Pointer Register bit assignments.

BitsTypeNameFunction
[CSETB_ADDR_WIDTH-1:0]R/WRAM Write Pointer, RWPSets the write pointer used to write entries from the CoreSight bus into the Trace RAM

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