Description of Operation
8-8
ADSP-BF537 Blackfin Processor Hardware Reference
serial connection composed of the
MDC
(management data clock) output
signal and the
MDIO
(management data input/output) bidirectional data
.
The MII management logical interface specifies:
• A set of 16-bit device control/status registers within PHYs, includ-
ing both required registers with standardized bit definitions as well
as optional vendor-specified registers
• A 5-bit device addressing scheme which allows the MAC to select
one of up to 32 externally-connected PHY devices
• A 5-bit register addressing scheme for selecting the target register
within the addressed device
• A transfer frame protocol for 16-bit read and write accesses to PHY
registers via the
MDC
and
MDIO
signals under control of the MAC
(PHY devices may not directly initiate
MDIO
transfers.)
Standard PHY control and status registers provide device capability status
bits (for example, auto-negotiation, duplex modes, 10/100 speeds and
protocols), device status bits (for example, auto-negotiation complete, link
status, remote fault), and device control bits (for example, reset, speed
selection, loopback, and auto-negotiation start).
The transfer frame protocol defines a MDC clock at a nominal period of
400ns, and an MDIO frame up to 64 bits in length. The MDIO frame
consists of an optional 32-bit preamble driven by the MAC, 14 control
bits driven by the MAC including the opcode and addresses, a 2-bit turn-
around sequence, and a 16-bit data transfer driven either by the MAC or
the PHY. Note that various PHYs support optional features such as
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...