upd7566a Renesas Electronics Corporation., upd7566a Datasheet - Page 22

• Manufacturer Part Number: upd7566a
• Description: 4-bit Single-chip Microcomputer
• Manufacturer: Renesas Electronics Corporation.

22
2.12
test request flags, INT0 RQF and INTT RQF, are set by two kinds of test sources (external test input (INT0) and timer
overflow (INTT)). The SM3 flag determines whether or not inputting signals to the INT0 pin is enabled. The test
request flag control circuit checks the contents of the test request flags, when an SKI instruction is executed, and
resets the flags.
is enabled.
to be set, the HALT modes are released.
disabled as the initial condition after the RESET signal has been applied.
Note indicates that an instruction has been executed.
The test control circuit consists of two test flags, a flag called SM3, and a test request flag control circuit. The
The SM3 flag is set by an OPL (L = 0FH) instruction (corresponding to A3). When this flag is 1, the INT0 input
The INT0 RQF flag is set when the rising edge is detected on the INT0 pin, and is reset by an SKI instruction.
The INTT RQF flag is set when an overflow occurs in the timer, and is reset by an SKI or TIMER instruction.
The signals output by the test request flags are used to release the HALT modes. If one of or both the flags were
When the RESET signal is input, both the test request flags and SM3 flag are reset. Therefore, INT0 input is
INT0
INTT
TEST CONTROL CIRCUIT
SM3
OPL
Note
EDGE GATE
EDGE GATE
NONSYNC
NONSYNC
Fig. 2-13 Test Control Circuit
Internal bus
TIMER
Note
CONTROL
TEST RQF
R
R
S
S
SKI
RQF
RQF
INTT
INT0
Note
Q
Q
PD7566A, 7566A(A)
HALT
RELEASE