UM1015
Block diagram
Doc ID 18124 Rev 1
9/38
2.0.2
Static memory subsystem (Serial Flash memory)
The SPEAr320 MPU supports up to 16 Mbytes of Serial Flash memory. Place and route for
2 blocks of 8 Mbytes are provided on the board, but only one is populated. It is based on an
M25P64-VMF6P (Numonix) Serial Flash memory device.
Resistor R8 protects the Flash memory from any unwanted write access.
2.0.3 USB
2.0
subsystem
Host ports
The board has two host ports that are fully compliant with the USB 2.0 specification (two
controllers with one port each). This means that the two hosts can work in concurrent mode
with the maximum possible bandwidth. Each host has also full control of the VBUS supplied
by the ST2052 power switch that also provides over current protection in case of a short
circuit in the USB cable.
Device port
The board has one USB 2.0 device port.
2.0.4 Debug
interface
The JTAG interface can be used for
static
debugging, which means that it is possible to set
a breakpoint, and when the system stops, verify the contents of the memory or registers, or
both, and modify them if needed.
To select the debug feature, set Switch SW1 bits [2:1].
For more information on the ETM interface, refer to the trace box manufacturer’s
documentation (www.lauterbach.com, www.agilent.com, www.yokogawa.com).
2.0.5 Serial
interface
One serial interface port is available. Typically used as an OS monitor, this port is available
on the J17 connector. It is possible to simulate a cross cable by changing the position of the
J22 jumpers.
Figure 3.
Serial cable setting
Table 1.
Switch SW1 bits [2:1]
Bit 2
Bit 1
Description
0
0
No debug features available
0
1
The ARM JTAG is connected to J4
Nul
Modem
Cable
J22
2
4
1
3
Cross
Cable
J22
2
4
1
3
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