Sun Microsystems Ultra 5, Service Manual

Page: 93 / 258

Chapter 4 Troubleshooting Procedures 4-21
4.7.2.7 Parallel Port Diagnostic
To start the parallel port diagnostic, type
6
at the OBDiag menu prompt. The parallel
port diagnostic performs the following:
1.
sio-passive-lb
– Sets up the SuperIO configuration register to enable
extended/compatible parallel port select, then does a write 0, walk-one, write 0 x
ff to the data register. It verifies the results by reading the status register.
2.
dma_read
– Enables ECP mode, ECP DMA configuration, and FIFO test mode.
Transfers 16 bytes of data from memory to the parallel port device and then
verifies the data is in TFIFO.
The following code example shows the parallel port output message.
4.7.2.8 Serial Port A Diagnostic
To start the serial port A diagnostic, type
7
at the OBDiag menu prompt. The serial
port A diagnostic invokes the
uart_loopback
test. This test transmits and receives
128 characters and checks serial port A transaction validity.
The following code example shows the serial port A output message.
CODE EXAMPLE 4-14
Parallel Port Output Message
Enter (0-12 tests, 13 -Quit, 14 -Menu) ===> 6
TEST='parallel_port_test'
SUBTEST='dma_read'
Enter (0-12 tests, 13 -Quit, 14 -Menu) ===>
CODE EXAMPLE 4-15
Serial Port A Output Message
Enter (0-12 tests, 13 -Quit, 14 -Menu) ===> 7
TEST='uarta_test'
BAUDRATE='1200'
SUBTEST='internal_loopback'
BAUDRATE='1800'
SUBTEST='internal_loopback'
BAUDRATE='2400'
SUBTEST='internal_loopback'
BAUDRATE='4800'
SUBTEST='internal_loopback'