NEC uPD78054(A) Manuale Utente

507

CHAPTER 21 INTERRUPT AND TEST FUNCTIONS

Internal bus

Test input
signal

Standby
release signal

21.5 Test Functions

Upon occurrence of watch timer overflow and the detection of the falling falling edge of port 4, the corresponding

test input flag is set (1) and a standby release signal is generated. Unlike in the case of interrupt functions, vector

processing is not performed.

There are two test input sources as shown in Table 21-5. The basic configuration is shown in Figure 21-18.

Table 21-5. Test Input Factors

Test Input Factors

Name

Trigger

INTWT

Watch timer overflow

Internal

INTPT4

Falling edge detection at port 4

External

Figure 21-18. Basic Configuration of Test Function

Remark

IF: test input flag

MK: test mask flag

21.5.1 Registers controlling the test function

The test function is controlled by the following three registers.

• Interrupt request flag register 1L (IF1L)

• Interrupt mask flag register 1L (MK1L)

• Key return mode register (KRM)

The names of the test input flags and test mask flags corresponding to the test input signals are listed in Table

21-6.

Table 21-6. Flags Corresponding to Test Input Signals

Test input signal name

Test input flag

Test mask flag

INTWT

WTIF

WTMK

INTPT4

KRIF

KRMK

Internal/

external