13-10
MCF5272 User’s Manual
GCI/IDL Block
local-loopback mode, the information transmitted on the Dout pin is echoed back on Din
during the same time slot.
The PLIC transmitter and receiver should both be disabled when switching between modes.
13.2.4.1 Automatic Echo Mode
The port automatically retransmits the received data on a bit-by-bit basis in this mode. The
local CPU-to-receiver communication continues normally, but the CPU-to-transmitter link
is disabled. While in this mode, received data is clocked on the receiver clock and
retransmitted on transmit Dout pin.
13.2.4.2 Local Loopback Mode
TxData is internally connected to RxData in this mode. This mode is useful for testing the
operation of a local port by sending data to the transmitter and checking data assembled by
the receiver. In this manner, correct channel operations can be assured. Also, both
transmitter and CPU-to-receiver communications continue normally in this mode. While in
this mode, the receive Din pin is ignored, the transmit Dout is held marking, and the
receiver is clocked by the transmitter clock.
13.2.4.3 Remote Loopback Mode
The channel automatically transmits received data on the transmit Dout pin on a bit-by-bit
basis in this mode. The local CPU-to-transmitter link is disabled. This mode is useful in
testing receiver and transmitter operation of a remote channel. While in this mode, the
receiver clock is used for the transmitter.
Figure 13-9. GCI/IDL Loopback Mode
Disabled
CPU
Rx
Tx
Disabled
(a) Automatic Echo
Disabled
CPU
Rx
Tx
Disabled
(b) Local Loopback
Din
Dout
Din
Dout
CPU
Rx
Tx
(c) Remote Loopback
Din
Dout
Disabled
Disabled
Disabled
Disabled
Summary of Contents for DigitalDNA ColdFire MCF5272
Page 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Page 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Page 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Page 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Page 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Page 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Page 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Page 338: ...13 44 MCF5272 User s Manual Application Examples ...
Page 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Page 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Page 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Page 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...