GS1532 Data Sheet
Table 1-1: Pin Descriptions (Continued)
Pin
Name
Timing
Type
Description
Number
25
RESET_TRST
Non
Input
CONTROL SIGNAL INPUT
Synchronous
Signal levels are LVCMOS/LVTTL compatible.
Used to reset the internal operating conditions to default settings and to
reset the JTAG test sequence.
Host Mode (JTAG/HOST = LOW)
When asserted LOW, all functional blocks will be set to default conditions
and all input and output signals become high impedance, including the
serial digital outputs SDO and SDO.
Must be set HIGH for normal device operation.
JTAG Test Mode (JTAG/HOST = HIGH)
When asserted LOW, all functional blocks will be set to default and the
JTAG test sequence will be held in reset.
When set HIGH, normal operation of the JTAG test sequence resumes.
26
JTAG/HOST
Non
Input
CONTROL SIGNAL INPUT
Synchronous
Signal levels are LVCMOS/LVTTL compatible.
Used to select JTAG Test Mode or Host Interface Mode.
When set HIGH, CS_TMS, SDOUT_TDO, SDI_TDI and SCLK_TCK are
configured for JTAG boundary scan testing.
When set LOW, CS_TMS, SDOUT_TDO, SDI_TDI and SCLK_TCK are
configured as GSPI pins for normal host interface operation.
27
CS_TMS
Synchronous
with
Input
CONTROL SIGNAL INPUT
Signal levels are LVCMOS/LVTTL compatible.
SCLK_TCK
Chip Select / Test Mode Select
Host Mode (JTAG/HOST = LOW)
CS_TMS operates as the host interface chip select, CS, and is active
LOW.
JTAG Test Mode (JTAG/HOST = HIGH)
CS_TMS operates as the JTAG test mode select, TMS, and is active
HIGH.
NOTE: If the host interface is not being used, tie this pin HIGH.
28
SDOUT_TDO
Synchronous
with
Output
CONTROL SIGNAL OUTPUT
Signal levels are LVCMOS/LVTTL compatible.
SCLK_TCK
Serial Data Output / Test Data Output
Host Mode (JTAG/HOST = LOW)
SDOUT_TDO operates as the host interface serial output, SDOUT, used
to read status and configuration information from the internal registers of
the device.
JTAG Test Mode (JTAG/HOST = HIGH)
SDOUT_TDO operates as the JTAG test data output, TDO.
21498 - 6 June 2005
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GENNUM [ GENNUM CORPORATION ]
