Epson ARM720T Benutzerhandbuch

The ARM720T processor uses a single clock, HCLK, as both the main system clock and the 

JTAG clock. You must connect the processor clock to both HCLK and TCK on the ETM. You 

can then use TCKEN to control the JTAG interface.
To trace through a warm reset of the ARM720T processor, use the TAP reset (connect nTRST 

to DBGnTRST) to reset the ETM7 state. 
For more information about ETM7 clocks and resets, see the 

ETM7 Technical Reference 

Manual

.

It is recommended that you connect together the DBGRQ output of the ETM7 to the DBGRQ 

input of the ARM720T processor. If this input is already in use, you can OR the DBGRQ inputs 

together. See the 

ETM7 Technical Reference Manual

 for more details.

The ARM720T processor does not provide a scan chain expansion input. ARM Limited 

recommends that you connect the ARM720T processor and the ETM7 TAP controllers in 

parallel. For more details, see the 

ETM7 (Rev 1) Technical Reference Manual

.

e

a.

See 

b.

See 

c.

See 

d.

Leave this pin unconnected.

e.

See 

Table 10-1  Connections between the ETM7 macrocell and the ARM720T processor (continued)