GD82559C S L3DF Intel, GD82559C S L3DF Datasheet - Page 57

• Manufacturer Part Number: GD82559C S L3DF
• Manufacturer: Intel

Specifications of GD82559C S L3DF

• Lead Free Status / Rohs Status: Not Compliant

6.0
6.1
6.2
6.3
6.3.1
Datasheet
Figure 17. Modem Read/Write Cycles
82559 Modem Functionality
The local port mimics the standard 8-bit interface of a modem to the host system and emulates a
16550 Universal Asynchronous Receiver/Transceiver (UART) modem interface. The modem
interface includes the following:
PCI Address Mapping to the Modem
The modem can be accessed by the PCI bus through either I/O or memory mapping.
Modem Read and Write Cycles
Basic read/write cycles to the modem device are shown in the figure below.
Modem and Preboot eXtension Environment Coexistence
The 82559 C-Step local bus interface supports either a Flash device or modem without external
support. In addition, the 82559 can also support both devices concurrently on the bus. Support is
provided through the use of the Security ASIC Chip Select (CFCS#) pin by using it in conjunction
with the Flash Chip Select (FLCS#) signal to enable the target device.
Programming Details
For designs that use both Flash and modem devices, the 82559 C-step supports the coexistence of
BootROM accesses (for Preboot eXtension Environment [PXE] code) and modem:
Modem Data In / Out
1. Set the EEPROM’s MDM bit.
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Modem WE# / RD#
Modem AEN (CS#)
Modem IOCHRDY
Modem Addrsess
8-bit data bus: FLD[7:0]
Control signals: AEN (FLCS#), MCNTSM# (FLA[12]), MINT (FLA[11]), MRING#
(FLA[10]), MRST (FLA[9]), RD# (FLOE#), and WR# (FLWE#)
4 address lines
Networking Silicon — 82559
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