isp1181 NXP Semiconductors, isp1181 Datasheet - Page 21

• Manufacturer Part Number: isp1181
• Description: Isp1181 Full-speed Universal Serial Bus Interface Device
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 08938
Product data
Fig 7. Suspend and resume timing for powered-off application.
SUSPEND
GOSUSP
WAKEUP
11.1.1 Powered-off application
In powered-off application (PWROFF = 1 in the Hardware Configuration Register) the
supply of the CPU and other parts of the circuit is removed during ‘suspend’ state.
The SUSPEND output is active HIGH during ‘suspend’ state, making it suitable as a
power switch control signal, e.g. for an external oscillator.
Input pins of ISP1181 are pulled to ground via the pin buffers. Outputs are made
three-state to prevent current flowing in the application. Bi-directional pins are made
three-state and must be pulled to ground externally by the application. The power
supply of external pull-ups must also be removed to reduce power consumption.
Table 12:
[1]
Pin
A0
DATA[15:0]
SUSPEND
WAKEUP
INT
RESET
CS
RD
WR
XTAL1
CLKOUT
4. To meet the ‘suspend’ current requirements for a bus-powered device, the
5. When the firmware has set and cleared the GOSUSP bit in the Mode Register,
internal clocks must be switched off by clearing bit CLKRUN in the Hardware
Configuration Register.
the ISP1181 enters ‘suspend’ state. In powered-off application, the ISP1181
asserts output SUSPEND and switches off the internal clocks after 2 ms.
‘Externally driven’ refers to logic outside the ISP1181.
2 ms
Pin states in powered-off application
Type
I
I/O (three-state)
O
I
O
I
I
I
I
I
O
Rev. 04 — 30 October 2001
Appropriate state
inactive
ISP1181 drives logic 1
inactive
powered off; internally connected to ground (logic 0)
externally driven
powered off; internally connected to ground (logic 0)
powered off; internally connected to ground (logic 0)
powered off; internally connected to ground (logic 0)
powered off; internally connected to ground (logic 0)
ISP1181 drives logic 0, if the NOLAZY bit is set to
logic 1 in the Hardware Configuration Register
0.5 ms
[1]
to logic 1
© Koninklijke Philips Electronics N.V. 2001. All rights reserved.
Full-speed USB interface
ISP1181
MGS782
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