DS785UM1
9-3
Copyright 2007 Cirrus Logic
1/10/100 Mbps Ethernet LAN Controller
EP93xx User’s Guide
9
9
9
The RAM blocks are interleaved in the AHB address space. AHB address bits 0 and 1 are
byte selects and must be zero for direct access. AHB address bit 2 selects the left or right
RAM array, which is the Transmit or Receive array. AHB address bits 3,4, and 5 perform a 1-
of-8 column select. Address bit 6 selects the even or odd row address. Address bits 7, 8, 9,
and 10 decode the rows. Thus from an AHB addressing perspective, the MAC FIFOs are one
large RAM array.
defines the FIFO RAM address map as it appears in the address space. Address
are in byte units. All data transfers to the FIFO RAM are restricted to words.
Caution: Accessing the FIFO RAM while the MAC is operating will likely cause a
malfunction.
There is no arbitration logic between direct AHB access and MAC Descriptor Processor
access.
The MAC configurations registers and FIFO RAMs are only word accessible
9.1.2 MAC Engine
The MAC engine is compliant with the requirements of ISO/IEC 8802-3 (1993), Sections 3
and 4.
9.1.2.1 Data Encapsulation
In transmission, the MAC automatically prepends the preamble, and computes and appends
the FCS. The data after the SFD and before the FCS is supplied by the host as the
transmitted data. FCS generation by the MAC may be disabled by setting InhibitCRC bit in
the Transmit Frame Descriptor. Refer to
.
Table 9-1. FIFO RAM Address Map
FIFO RAM Address Map
Usage
0x8001_4000 to 0x8001_47FF
Rx Data
0x8001_4800 to 0x8001_4FFF
Tx Data
0x8001_5000 to 0x8001_503F
Rx Status
0x8001_5040 to 0x8001_507F
Tx Status
0x8001_5080 to 0x8001_50BF
Rx Descriptor
0x8001_50C0 to 0x8001_50FF
Tx Descriptor
Summary of Contents for EP93 Series
Page 28: ...P 6 DS785UM1 Copyright 2007 Cirrus Logic Preface EP93xx User s Guide PP P ...
Page 162: ...5 36 DS785UM1 Copyright 2007 Cirrus Logic System Controller EP93xx User s Guide 55 5 ...
Page 576: ...15 18 DS785UM1 Copyright 2007 Cirrus Logic UART2 EP93xx User s Guide 1515 15 ...
Page 634: ...17 38 DS785UM1 Copyright 2007 Cirrus Logic IrDA EP93xx User s Guide 1717 17 ...
Page 648: ...19 6 DS785UM1 Copyright 2007 Cirrus Logic Watchdog Timer EP93xx User s Guide 1919 19 ...
Page 688: ...21 32 DS785UM1 Copyright 2007 Cirrus Logic I2S Controller EP93xx User s Guide 2121 21 ...
Page 790: ...27 20 DS785UM1 Copyright 2007 Cirrus Logic IDE Interface EP93xx User s Guide 2727 27 ...
Page 808: ...28 18 DS785UM1 Copyright 2007 Cirrus Logic GPIO Interface EP93xx User s Guide 2828 28 ...