SH7262/SH7264 Group
Hardware Design Guide
REJ06B0999-0100 Rev. 1.00
Page 25 of 36
Jun. 30, 2010
6.5 USB
Pins
For details on handling pins to use the USB 2.0 host or function module (USB module), refer to the application note
"SH7262/SH7264 Group Guidelines for Hi-Speed USB 2.0 Board Design".
6.6 Terminating
Pins
6.6.1
Unused Pins
Table 9 lists the handling of unused pins.
Table 9 Unused Pins Handling
Pin Name
Handling
NMI
Fix at high level (pull up or connect to the power supply)
DP, DM, VBUS
Connect to the USBDPVss
REFRIN
Connect to the USBAPVcc via 5.6 k
Ω
± 20% resistor
USB power supply (USBAPVcc, USBAPVss,
USBDPVcc, USBDPVss, USBAVcc, USBAVss,
USBDVcc, USBDVss, USBUVcc, USBUVss)
Connect to the power supply, ground
AVref
Connect to the AVcc
ADC power supply (AVcc, AVss)
Connect to the power supply, ground
Other input-only pins
Fix the level (pull up, pull down, connect to the power
supply or ground)
Other I/O-only pins
Set to input pin and fix the level (pull up or pull down)
Or set to the output pin and open
Output-only pins
Leave open
ASEMD#
Fix to high level (pull up or connect to the power supply)
TRST#
Fix to low level (pull down or connect to ground)
TCK, TMS, TDI
Fix the level (pull up, pull down, connect to the power
supply or ground)
TDO, ASEBRKAK#/ASEBRK#
Leave open
Note: We recommend using pull-up or pull-down resistors between 4.7 k
Ω
to 100 k
Ω
.
6.6.2 Used
Pins
The engineer may still need to terminate “used” pins in his design with either pull-up or pull-down resistors. During the
RESET cycle GPIO pins will revert to high impedance inputs and remain that way until the hardware setup code is
executed, which could be considerable depending on the boot time. The engineer will need to evaluate his design and
determine if pull-up or pull-down resistors are required in his design. A prime example would be power circuits, where
the engineer will want to passively pull them to the “inactive” state to avoid hardware damage or malfunction.