ISP1581
USB 2.0 HS interface device
Philips Semiconductors
9.2.2 Mode register (address: 0CH)
This register consists of 1 byte (bit allocation: see Table 7). In 16-bit bus mode the
upper byte is ignored.
The Mode register controls the resume, suspend and wake-up behaviour, interrupt
activity, soft reset, clock signals and SoftConnect operation. This register also
controls the Power Off mode during ‘suspend’ state.
Table 7: Mode register: bit allocation
Bit
7
6
5
4
3
2
1
PWROFF
0
0
SOFTCT
0
Symbol
Reset
CLKAON SNDRSU
GOSUSP
SFRESET GLINTENA WKUPCS
0
0
0
0
0
0
0
0
0
0
0
Bus reset
Access
unchanged
R/W
unchanged unchanged
R/W R/W
R/W
R/W
R/W
R/W
R/W
Table 8: Mode register: bit description
Bit
Symbol
Description
7
CLKAON
Clock Always On: A logic 1 indicates that the internal clocks
are always running even during ‘suspend’ state. A logic 0
switches off the internal oscillator and PLL, when they are not
needed. During ‘suspend’ state, this bit must be set to logic 0 to
meet the suspend current requirements. The clock is stopped
after a delay of approximately 2 ms, following the setting of bit
GOSUSP.
6
SNDRSU
Send Resume: Writing a logic 1 followed by a logic 0 will
generate an upstream ‘resume’ signal of 10 ms duration, after a
5 ms delay.
5
4
GOSUSP
SFRESET
Go Suspend: Writing a logic 1 followed by a logic 0 will activate
‘suspend’ mode.
Soft Reset: Writing a logic 1 followed by a logic 0 will enable a
software-initiated reset to ISP1581. A soft reset is similar to a
hardware-initiated reset (via the RESET pin).
3
GLINTENA
Global Interrupt Enable: A logic 1 enables all interrupts.
Individual interrupts can be masked OFF by clearing the
corresponding bits in the Interrupt Enable register. Bus reset
value: unchanged.
2
1
WKUPCS
PWROFF
Wake-up on Chip Select: A logic 1 enables remote wake-up
via a LOW level on input CS.
Power Off mode: A logic 1 enables powering-off during
‘suspend’ state. Output SUSPEND is configured as a power
switch control signal for external devices (HIGH during
‘suspend’). Bus reset value: unchanged.
0
SOFTCT
SoftConnect: A logic 1 enables the connection of the 1.5 kΩ
pull-up resistor on pin RPU to the D+ line. Bus reset value:
unchanged.
9397 750 07648
© Philips Electronics N.V. 2000. All rights reserved.
Objective specification
Rev. 02 — 23 October 2000
14 of 73
NXP [ NXP ]
