![](http://datasheet.mmic.net.cn/330000/PM6344-RI_datasheet_16444359/PM6344-RI_189.png)
STANDARD PRODUCT
PMC-Sierra, Inc.
PM6344 EQUAD
PMC-951013
ISSUE 5
QUADRUPLE E1 FRAMER
176
11
TEST FEATURES DESCRIPTION
Simultaneously asserting the CSB, RDB and WRB inputs causes all output pins
and the data bus to be held in a high-impedance state. This test feature may be
used for board testing.
Test mode registers are used to apply test vectors during production testing of
the EQUAD. Test mode registers (as opposed to normal mode registers) are
mapped into addresses 200H-3FFH.
Test mode registers may also be used for board testing. When all of the
constituent Telecom System Blocks within the EQUAD are placed in test mode 0,
device inputs may be read and device outputs may be forced via the
microprocessor interface (refer to the section "Test Mode 0" for details).
Notes on Test Mode Register Bits:
1. Writing values into unused register bits has no effect. Reading unused bits
can produce either a logic 1 or a logic 0; hence unused register bits should be
masked off by software when read.
2. Writeable test mode register bits are not initialized upon reset unless
otherwise noted.
11.1 Test Mode 0
In test mode 0, the EQUAD allows the logic levels on the device inputs to be read
through the microprocessor interface, and allows the device outputs to be forced
to either logic level through the microprocessor interface.
To enable test mode 0, the IOTST bit in the Test Mode Select Register is set to
logic 1 and the following addresses must be written with 00H: 211H, 219H,
21DH, 221H, 231H, 235H, 239H, 241H, 245H, 291H, 299H, 29DH, 2A1H, 2B1H,
2B5H, 2B9H, 2C1H, 2C5H, 311H, 319H, 31DH, 321H, 331H, 335H, 339H, 341H,
345H, 391H, 399H, 39DH, 3A1H, 3B1H, 3B5H, 3B9H, 3C1H, and 3C5H. Also, to
enable input and output signals to propagate through the interface blocks, the
value 00H must be written to addresses 001H, 002H, 003H, 004H, 081H, 082H,
083H, 084H, 101H, 102H, 103H, 104H, 181H, 182H, 183H, and 184H. The
value 02H must be written to addresses 007H, 087H, 107H, and 187H.
Reading the following address locations returns the values for the indicated
inputs :