zl50409 Zarlink Semiconductor, zl50409 Datasheet - Page 20

• Manufacturer Part Number: zl50409
• Description: Managed 9-port 10/100m Ethernet Switch
• Manufacturer: Zarlink Semiconductor

1.5
TSTOUT[15:0] and M[7:0]_TXEN pins serve as bootstrap pins during device power-up or reset. Please refer to
“Typical Reset & Bootstrap Timing Diagram” on page 123 for more information on when the bootstrap pins are
sampled. The bootstrap pins require external pull-up/down resistors for proper operation.
The table below summarizes the bootstrap options.
1.5.1
The following are the recommended default settings for the bootstrap options:
•
CPU Interface
Ethernet Interface
Misc. Features
Unmanaged/Lightly Managed
•
•
Bootstrap Options
Reserved/Manufacturing bootstraps
-
-
CPU Interface:
-
-
Recommended Default Bootstrap Settings
TSTOUT[15:13,8] must be pulled-up
TSTOUT[10] must be pulled-down
Strobe debounce bootstrap, TSTOUT[0], should be normally pulled-up, unless you wish to disable the
debounce logic
CPU Interface bootstrap, TSTOUT[3:1], should be pulled-up to indicate unmanaged SSI CPU
interface. To enable SSI-only lightly managed mode, pulled-down TSTOUT[3]. To enable SSI+MII
lightly managed mode, pulled-down TSTOUT[3,1]
Feature
The ZL50409 supports module hotswap on all it's ports. This is enabled via
The ZL50409 allows the selection of 5 different management interfaces:
8/16-bit parallel, serial with MII, serial only and unmanaged serial with I2C
EEPROM.
TSTOUT[3:1] is used to select the interface options mentioned above. If the
serial interface is selected, addition bootstrap options are required:
•
•
Also, in unmanaged mode, an optional I
the device at power-up or reset. TSTOUT[7] selects the EEPROM option.
TSTOUT[9]. When enabled, bootstrap pins M[7:0]_TXEN (ports 0-7) are used
to specify the module type to support multiple ethernet interfaces during
module hotswap.
Another feature is the MAC power savings mode. When enabled via
TSTOUT[11], each port's MAC will detect inactivity on the port and go into a
power savings state. When activity is detected once again on the port, the MAC
will come out of this state.
One other feature selected via bootstrap is Timeout Reset Enable
(TSTOUT[12]). This enables a monitoring block with the device which will
detect if any hardware state machine is in a non-idle state for more than 5
seconds.
Refer to section 2.7 for more details on this feature.
TSTOUT[0] enables or disables the DEBOUNCE feature (refer to
“Synchronous Serial Interface” on page 32)
TSTOUT[6:4] selects the device ID
Table 4 - Bootstrap Features
Zarlink Semiconductor Inc.
ZL50409
20
Description
2
C EEPROM can be used to configure
Data Sheet