
Philips Semiconductors
ISP1181B
Full-speed USB peripheral controller
Product data
Rev. 02 — 07 December 2004
28 of 70
9397 750 13958
Koninklijke Philips Electronics N.V. 2004. All rights reserved.
12.1.4
Write/Read Hardware Configuration
This command is used to access the Hardware Configuration Register, which
consists of 2 bytes. The first (lower) byte contains the device configuration and
control values, the second (upper) byte holds the clock control bits and the clock
division factor. The bit allocation is given in
Table 20
. A bus reset will not change any
of the programmed bit values.
The Hardware Configuration Register controls the connection to the USB bus, clock
activity and power supply during ‘suspend’ state, output clock frequency, DMA
operating mode and pin configurations (polarity, signalling mode).
Code (Hex): BA/BB —
write/read Hardware Configuration Register
Transaction —
write/read 2 bytes
Table 20:
Bit
Symbol
Reset
Access
Bit
Symbol
Reset
Access
Hardware Configuration Register: bit allocation
15
14
reserved
EXTPUL
0
0
R/W
R/W
7
6
DAKOLY
DRQPOL
0
1
R/W
R/W
13
12
11
10
9
8
NOLAZY
1
R/W
5
DAKPOL
0
R/W
CLKRUN
0
R/W
4
EOTPOL
0
R/W
CLKDIV[3:0]
0
0
1
1
R/W
3
R/W
2
R/W
1
INTLVL
0
R/W
R/W
0
INTPOL
0
R/W
WKUPCS
0
R/W
PWROFF
0
R/W
Table 21:
Bit
15
14
Hardware Configuration Register: bit description
Symbol
Description
-
reserved
EXTPUL
A logic 1 indicates that an external 1.5 k
pull-up resistor is
used on pin D
+
and that SoftConnect is not used. Bus reset
value: unchanged.
NOLAZY
A logic 1 disables output on pin CLKOUT of the LazyClock
frequency (100 kHz
±
50 %) during ‘suspend’ state. A logic 0
causes pin CLKOUT to switch to LazyClock output after
approximately 2 ms delay, following the setting of bit GOSUSP
in the Mode Register. Bus reset value: unchanged.
CLKRUN
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 made 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 in the
Mode Register. Bus reset value: unchanged.
CLKDIV[3:0]
This field specifies the clock division factor N, which controls the
clock frequency on output CLKOUT. The output frequency in
MHz is given by
3 MHz to 48 MHz (N = 0 to 15). with a reset value of 12 MHz
(N = 3). The hardware design guarantees no glitches during
frequency change. Bus reset value: unchanged.
DAKOLY
A logic 1 selects DACK-only DMA mode. A logic 0 selects 8237
compatible DMA mode. Bus reset value: unchanged.
13
12
11 to 8
. The clock frequency range is
7
48
N
1
+
(
)