CS8900-CQ3 Cirrus Logic, CS8900-CQ3 Datasheet - Page 20

• Manufacturer Part Number: CS8900-CQ3
• Description: Crystal LAN ISA Ethernet Controller
• Manufacturer: Cirrus Logic

After a reset, the ISA bus outputs INTRx and
DMARQx are 3-Stated, thus avoiding any interrupt
or DMA channel conflicts on the ISA bus at power-
up time.
3.3.4 Initialization
After each reset (except EEPROM Reset), the
CS8900A checks the sense of the EEDataIn pin to
see if an external EEPROM is present. If EEDI is
high, an EEPROM is present and the CS8900A au-
tomatically loads the configuration data stored in
the EEPROM into its internal registers (see next
section). If EEDI is low, an EEPROM is not
present and the CS8900A comes out of reset with
the default configuration shown in Table 3.
A low-cost serial EEPROM can be used to store
configuration information that is automatically
loaded into the CS8900A after each reset (except
EEPROM reset). The use of an EEPROM is op-
tional.
The CS8900A operates with any of six standard
EEPROM’s shown in Table 4.
20
CIRRUS LOGIC PRODUCT DATA SHEET
* I/O base address is unaffected by Software Suspend mode.
‘C46 (non-sequential)
‘CS46 (sequential)
‘C56 (non-sequential)
‘CS56 (sequential)
‘C66 (non-sequential)
‘CS66 (sequential)
PacketPage
Address
002Ch
010Ch
0020h
0022h
0024h
0026h
0028h
002Ah
0030h
0034h
0102h
0104h
0106h
0108h
010Ah
010Eh
0110h
0112h
0114h
0116h
0118h
EEPROM Type
Crystal LAN™ ISA Ethernet Controller
Table 4. Supported EEPROM Types
Table 3.
0300h
XXXX XXXX
XXXX X100
XXXX XXXX
XXXX XX11
0000h
X000h
0000h
XXX0 0000h Memory Base Address
XXX0 0000h Boot PROM Base
XXX0 0000h Boot PROM Address
0003h
0005h
0007h
0009h
000Bh
Undefined
Undefined
Undefined
00013h
0015h
0017h
Contents
Register
0019h
D
efault Configuration
I/O Base Address*
Interrupt Number
DMA Channel
DMA Start of Frame
Offset
DMA Frame Count
DMA Byte Count
Address
Mask
Register 3 - RxCFG
Register 5 - RxCTL
Register 7 - TxCFG
Register 9 - TxCMD
Register B - BufCFG
Reserved
Reserved
Reserved
Register 13 - LineCTL
Register 15 - SelfCTL
Register 17 - BusCTL
Register 19 - TestCTL
Register Descriptions
Size (16-bit words)
128
128
256
256
64
64
CS8900A
DS271PP3