Chapter 15: Serial Port Interface
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
15-18
15.10.2 Toshiba Mode
In the Toshiba Mode, all three interrupt channels are used to allow MicroDMA transfers to,
and from, the TSEI data register. Interrupt Channel 0 generates an interrupt on three
different sources. The first type of interrupt is generated on a transition of the MODF flag
from “0” to “1.” The WCOL interrupt is caused if the module is in the Slave Mode with TASM
equal to “0.” Finally, the SOVF flag causes an interrupt only if the module is configured as a
slave and TASM is asserted.
Both the TSRC and the TSTC flags in the SESR register are asserted simultaneously after a
transfer is complete. Both flags trigger their own interrupt. The TSRC flag generates an
interrupt on channel 1 on a transition from “0” to “1”. This flag can be cleared by either
reading to the SEDR register or by writing a “1” value to this flag.
The TSTC flag generates an interrupt on channel 2 on a transition from “0” to “1.” This flag is
cleared by either writing the SEDR register or by writing a “1” value to this flag.
When using with the MicroDMA, one of the interrupts can be used to trigger a MicroDMA
that reads the data from the TSEI register. The other interrupt can be used to trigger a
MicroDMA that writes a new value to the data register, thus initiating a new transfer.
TSEI Interrupt Channel 0 (TSIC0)
Interrupt on MODF or WCOL
1
or
SOVF
2
TSEI Interrupt Channel 1 (TSIC1)
Interrupt on TSRC
TSEI Interrupt Channel 2 (TSIC2)
Interrupt on TSTC
The SEIE bit is obsolete in the Toshiba Mode. The Interrupts are individually disabled at the
interrupt controller.
15.10.3 Interrupt Generation on TSIC0
If a flag in the SESR register that causes an interrupt shows a transition from “0” to “1,” an
interrupt will be generated if no other interrupt flag is already pending.
If an interrupt pulse has been generated by an interrupt source and the interrupt flag for this
source has not been cleared, another occurrence of the same source will not generate a
new interrupt pulse.
When the flag of a source that caused an interrupt is being cleared, a new interrupt can
occur on a different flag. This will happen immediately if another interrupt flag in the SESR
register is asserted and was not cleared together with the flag that caused the previous
interrupt.
1
Only if module is in the Slave Mode and TASM in the SESR register is not asserted.
2
Only if module is in the Slave Mode and TASM in the SESR register is asserted.
Summary of Contents for TMPR7901
Page 1: ...TX System RISC TX79 Family TMPR7901 Symmetric 2 way superscalar 64 bit CPU ...
Page 14: ...Handling Precautions ...
Page 15: ......
Page 17: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 41: ...4 Precautions and Usage Considerations 4 2 ...
Page 42: ...TX7901 User s Manual Rev 6 30T November 2001 DOCUMENT NUMBER M 99 00004 07 ...
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Page 260: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 2 ...