HI-6138 Datasheet, PDF (44/254 Pages) Holt Integrated Circuits – 40 MHz SPI Host Interface

HI-6138
Bit No.
2
Mnemonic
INTBUSY
Function
Report terminal Busy status for RT message interrupts; set WASBUSY flag bit 9 in log
buffer Interrupt Identification Word. See “Interrupt Log Buffer” on page 37.
Setting INTBUSY = 1 causes the WASBUSY status bit 9 to be set in the RT Interrupt
Identification Word (IIW) when an enabled interrupt event occurs with RT Busy status.
Therefore, RT subaddresses or mode codes with enabled message interrupts can
optionally report when Busy status applied during those events. For example, assume the
RT Rx subaddress 1 Interrupt When Accessed event (IWA) is enabled. If RT subaddress 1
sees a legal, valid receive message but the RT is Busy, the IWA and WASBUSY flags are
both set in the Interrupt Log Buffer’s written Interrupt Identification Word. If RT is not Busy,
only the IWA flag is set in the written IIW.
When INTBUSY is reset, terminal Busy status for interrupts is not reported; the WASBUSY
status bit in the logged RT Interrupt Identification Word is always 0.
Note 1: The Interrupt Log Buffer is updated only when enabled interrupt events occur. By
itself, RT Busy status is not an interrupt-causing event.
Note 2: INTBUSY bit 2 does not affect the “Remote Terminal (RT) Pending Interrupt
Register (0x0009)” on page 132; register bit 9 is reserved. Only WASBUSY bit 9 in the
Interrupt Log Buffer Interrupt Identification Word (IIW) is affected.
HOLT INTEGRATED CIRCUITS
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