Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet

Product codes

AT91SAM9N12-EK

Tightly-Coupled Memory Interface

ARM DDI0198D

5-7

5.2.2

Instruction TCM signals

The instruction side TCM signals are almost identical to the DTCM signals. All the
signals on the DTCM have an equivalent on the instruction side.

•

Control signals

—

IRCS

—

IRWAIT

—

IRIDLE

•

Address and attribute signals

—

IRSEQ

—

IRADDR[17:0]

—

IRWBL[3:0]

—

IRnRW

•

Data signals

—

IRRD[31:0]

—

IRWD[31:0]

•

DMA signals

—

IRDMAEN

—

IRDMACS

—

IRDMAADDR[17:0].

5.2.3

Differences between DTCM and ITCM

There are three differences between the DTCM and ITCM interfaces:

•

DMA to ITCM should not occur be performed unless IRIDLE is asserted

•

Only back-to-back transfers on the DTCM can be marked as sequential. On the
ITCM idle cycles may occur before requests marked as sequential.

•

Sequential write transfers will not occur on the ITCM.