hi-6131pqtf QuickLogic Corp, hi-6131pqtf Datasheet - Page 32

• Manufacturer Part Number: hi-6131pqtf
• Description: Mil-std-1553 / Mil-std-1760 3.3v Bc / Mt / Rt Multi-terminal Device
• Manufacturer: QuickLogic Corp

Bit No.
3
2
Mnemonic
BSDTXO
INTSEL
R/W
R/W
R/W
Reset
0
0
Function
Bus Shutdown Transmit Only.
The bit only applies when Remote Terminal RT1 and/or RT2 is enabled.
The BSDTXO bit determines how a 1553 bus inhibit works when (a) the
RTxINHA or RTxINHB bit is set in the RT Configuration Register, or (b)
the RT receives a valid “bus shutdown” mode code command, either
MC4 or MC21:
The HI-613x RT1 and RT2 automatically fulfill unconditional MC4 “bus
shutdown” in accordance with the BSDTXO setting, as well as MC5
“override bus shutdown.”
The AUTOBSD bit in the RT Configuration Register determines whether
conditional MC20 “selected bus shutdown” and MC21 “override selected
bus shutdown” are fulfilled automatically, or by host writes to the
RTxINHA or RTxINHB bits in the appropriate RT Configuration Register:
IRQ Output Type Select.
When this bit is 0, the IRQ (interrupt request) output generates a 1µs
negative pulse when enabled interrupt events occur. When this bit is
logic 1, the IRQ output consists of a continuous low level output requiring
host action to negate IRQ to the high state. The host can negate IRQ by
asserting the IRQACK input 250ns minimum, or by reading the pending
interrupt register(s) containing one or more interrupt-identification bits.
HOLT INTEGRATED CIRCUITS
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HI-6130, HI-6131
When the BSDTXO bit is reset, logic 1 for an RTxINHA or RTxINHB bit
in a RT Configuration Register (or a “bus shutdown” mode command
with auto shutdown enabled) inhibits both transmit and receive on
the selected bus.
When the BSDTXO bit is set, logic 1 for an RTxINHA or RTxINHB bit
in a RT Configuration Register (or a “bus shutdown” mode command
with auto shutdown enabled) inhibits transmit only on the selected
bus; but receive functions are unaffected. Valid commands are
heeded, but the RT transmits no responses. NOT RECOMMENDED.
When the AUTOBSD bit is logic 0 in the RT1 or RT2 Configuration
Register, automatic fulfillment is disabled for MC20 “selected
bus shutdown” and MC21 “override selected bus shutdown” mode
commands. The host fulfills bus shutdown and override by writing
the RTxINHA and RTxINHB bits in the appropriate RT Configuration
Register.
When the AUTOBSD bit is logic 1 in the RT1 or RT2 Configuration
Register, automatic fulfillment is enabled for MC20 “selected
bus shutdown” and MC21 “override selected bus shutdown” mode
commands. When the received mode data word matches the value
stored in the RT “Bus A (or B) Select” register, the RT automatically
fulfills MC20 “selected bus shutdown” in accordance with the
BSDTXO setting, as well as MC21 “override selected bus shutdown”.
Auto-shutdown bypasses the RTxINHA and RTxINHB bits in the RT
Configuration Register, but the upper 4 bits in the RT’s BIT Word
register indicate Tx and Rx bus shutdown status.
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