Chapter 10: Programmable Timer/Contents
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
10-15
(TMITMR) is set to “1”. When the TIIE bit is subsequently cleared to “0”, this causes the
interrupt logic to mask the inverted TIIS bit (and to not transmit it), effectively disabling the
interrupt request signal TMINTREQ*.
When the Timer Interval Interrupt status (TIIS) bit of the status register (TMTISR) is cleared
to “0” (by writing a “0” to it while servicing the interrupt), the timer interrupt request signal
TMINTREQ* is de-asserted High, effectively terminating the interrupt. Writing “1” to the TIIS
bit is ignored.
When the Timer Zero Clear Enable (TZCE) bit of the TMITMR Register is set to “1”, the 24-
bit counter is cleared to “0” and counting restarts, asserting the interrupt request signal when
the count value reaches the value in TMCPRA.
When the TZCE bit is “0”, counter operation is stopped when the count matches the value of
TMCPRA. This is summarized in the table below:
Table 10-12 Interrupt control with the TIIE and TZCE bits
TIIE
TZCE
Action or inaction when counter has reached the set up value
0
X
Timer Interval Interrupt Requests are disabled (masked out), and do not occur.
1
0
An Interrupt Request occurs. If the Timer Zero Clear Enable bit is cleared to “0” when an
interrupt is terminated (by clearing the TIIS bit), no further interrupts occur.
When the interrupt is terminated after TZCE is set to “1”, a timer interrupt recurs. This is
the same as when TIIE = 1 and TZCE = 1.
1
1
Timer Interval Interrupt Requests are enabled, and do occur periodically.
A copy of the count value in the 24-bit counter can be read from the Timer Read Register
(TMTRR).
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 ...
Page 43: ......
Page 259: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 1 13 Removed ...
Page 260: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 2 ...