w83196s-14 Winbond Electronics Corp America, w83196s-14 Datasheet - Page 5

• Manufacturer Part Number: w83196s-14
• Description: 100 Mhz Clock For Bx Chipset 2 Chip
• Manufacturer: Winbond Electronics Corp America

7. FUNCTIONAL DESCRIPTION
7.1 Power Mamagement Functions
All clocks can be individually enabled or disabled via the 2-wire control interface. On power up,
external circuitry should allow 3 ms for the VCOs to stabilize prior to enabling clock outputs to assure
correct pulse widths. When MODE = 0, pins 10 and 11 are inputs (PCI_STOP#), (CPU_STOP#),
when MODE = 1, these functions are not available. A particular clock could be enabled as both the 2-
wire serial control interface and one of these pins indicate that it should be enabled.
The W83196S-14 may be disabled in the low state according to the following table in order to reduce
power consumption. All clocks are stopped in the low state, but maintain a valid high period on
transitions from running to stop. The CPU and PCI clocks transform between running and stop by
waiting for one positive edge on PCICLK_F followed by negative edge on the clock of interest, after
which high levels of the output are either enabled or disabled.
7.2 2-Wire I
The clock generator is a slave I
for verification. All proceeding bytes must be sent to change one of the control bytes. The 2-wire
control interface allows each clock output individually enabled or disabled. On power up, the
W83196S-14 initializes with default register settings, and then it is optional to use the 2-wire control
interface.
The SDATA signal only changes when the SDCLK signal is low, and is stable when SDCLK is high
during normal data transfer. There are only two exceptions. One is a high-to-low transition on
SDATA while SDCLK is high used to indicate the beginning of a data transfer cycle. The other is a
low-to-high transition on SDATA while SDCLK is high used to indicate the end of a data transfer
cycle. Data is always sent as complete 8-bit bytes followed by an acknowledge generated.
Byte writing starts with a start condition followed by 7-bit slave address and a write command bit
[1101
reception of each byte, an acknowledge (low) on the SDATA wire will be generated by the clock chip.
Controller can start to write to internal I2C registers after the string of data. The sequence order is as
follows:
Bytes sequence order for I2C controller:
CPU_STOP#
Clock Address
A(6:0) & R/W
0
0
1
1
0010], command code checking [0000 0000], and byte count checking. After successful
2
C Control Interface
PCI_STOP#
Ack
0
1
0
1
8 bits dummy
Command code
2
C component which can be read back the data stored in the latches
CPUCLK1
RUNNING
RUNNING
LOW
LOW
Ack
- 5 -
PCICLK1:4
RUNNING
RUNNING
8 bits dummy
Byte count
LOW
LOW
Preliminary W83196S-14
Publication Release Date: March 1999
CPUCLK_F&
PCICLK_F
RUNNING
RUNNING
RUNNING
RUNNING
Ack
Byte0,1,2...
until Stop
XTAL & VCOs
RUNNING
RUNNING
RUNNING
RUNNING
Revision A1