8.10.00 J-TRACE ARM Segger Microcontroller Systems, 8.10.00 J-TRACE ARM Datasheet - Page 102

• Manufacturer Part Number: 8.10.00 J-TRACE ARM
• Description: JTAG EMULATOR ARM7/ARM9 ETM
• Manufacturer: Segger Microcontroller Systems
• Type: Emulatorr

Specifications of 8.10.00 J-TRACE ARM

• Contents: Emulation Module
• For Use With/related Products: ARM7, ARM9
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 899-1006

102
5.3.4
5.3.4.1 Fixed JTAG speed
5.3.4.2 Automatic JTAG speed
5.3.4.3 Adaptive clocking
J-Link / J-Trace (UM08001)
Table 5.5: Example scan chain configurations
The target device is marked in blue.
There are basically three types of speed settings:
•
•
•
These are explained below.
The target is clocked at a fixed clock speed. The maximum JTAG speed the target can
handle depends on the target itself. In general ARM cores without JTAG synchroniza-
tion logic (such as ARM7-TDMI) can handle JTAG speeds up to the CPU speed, ARM
cores
ARM966EJ-S) can handle JTAG speeds up to 1/6 of the CPU speed.
JTAG speeds of more than 10 MHz are not recommended.
Selects the maximum JTAG speed handled by the TAP controller.
Note:
because the CPU core may be clocked slower than the maximum JTAG speed.
If the target provides the RTCK signal, select the adaptive clocking function to syn-
chronize the clock to the processor clock outside the core. This ensures there are no
synchronization problems over the JTAG interface.
If you use the adaptive clocking feature, transmission delays, gate delays, and syn-
chronization requirements result in a lower maximum clock frequency than with non-
adaptive clocking.
Chip(IR len)
Device 0
Xilinx(8)
ARM(4)
ARM(4)
Fixed JTAG speed
Automatic JTAG speed
Adaptive clocking.
JTAG Speed
with
On ARM cores without synchronization logic, this may not work reliably,
JTAG
Chip(IR len)
Device 1
Xilinx(8)
Xilinx(8)
ARM(4)
synchronization
Chip(IR len)
Device 2
Xilinx(8)
ARM(4)
ARM(4)
CHAPTER 5
logic
© 2004-2011 SEGGER Microcontroller GmbH & Co. KG
Position
(such
0
2
1
as
ARM7-TDMI-S,
IR len
12
0
8
Working with J-Link and J-Trace
ARM946E-S,