isp1705 NXP Semiconductors, isp1705 Datasheet - Page 16

• Manufacturer Part Number: isp1705
• Description: Ulpi Hi-speed Usb Transceiver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
ISP1705_1
Product data sheet
Fig 7.
DATA[7:0]
RESET_N
CLOCK
NXT
STP
DIR
Interface behavior with respect to RESET_N
8.11.1 Interface protection
8.11.2 Interface behavior with respect to RESET_N
8.11.3 Interface behavior with respect to chip select
Hi-Z (input)
Hi-Z (input)
By default, the ISP1705 enables a weak pull-up resistor on STP. If the STP pin is
unexpectedly HIGH at any time, the ISP1705 will protect the ULPI interface by enabling
weak pull-down resistors on DATA[7:0].
The interface protect feature prevents unwanted activity of the ISP1705 whenever the
ULPI interface is not correctly driven by the link. For example, when the link powers up
more slowly than the ISP1705.
The interface protect feature can be disabled by setting the INTF_PROT_DIS bit to logic 1.
The use of the RESET_N pin is optional. When RESET_N is asserted (LOW), all logic in
the ISP1705 will be reset, including the analog circuitry and ULPI registers. During reset,
the link must drive DATA[7:0] and STP to LOW; otherwise undefined behavior may result.
When RESET_N is deasserted (HIGH), 60 MHz clock will start.
interface behavior when RESET_N is asserted (LOW), and subsequently deasserted
(HIGH). The behavior of
is not used, it must be connected to V
The use of chip select as a power-down control signal is optional. When chip select is
deasserted, the ISP1705 will 3-state ULPI pins and power-down the internal circuitry. If
chip select is not used as a power-down control signal, CHIP_SEL_N must be connected
to LOW.
subsequently deasserted.
Figure 8
Hi-Z (link must drive)
Hi-Z (link must drive)
shows the ULPI interface behavior when chip select is asserted and
Rev. 01 — 13 June 2008
Figure 7
applies only when chip select is asserted. If RESET_N
CC(I/O)
Hi-Z (input)
Hi-Z (input)
.
ULPI Hi-Speed USB transceiver
Figure 7
© NXP B.V. 2008. All rights reserved.
ISP1705
shows the ULPI
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