S1C62440/624A0/624C0/62480 TECHNICAL HARDWARE
EPSON
I-161
CHAPTER 15: SUMMARY OF NOTES
Sound generator
Serial interface
(SIN, SOUT, and SCLK)
(1) When using the serial interface in the master mode, the
synchronous clock uses the CPU system clock. Accord-
ingly, do not change the system clock (fOSC1
fOSC3)
while the serial interface is operating.
(2) Perform data writing/reading to data registers SD0–SD7
only while the serial interface is halted (i.e., the synchro-
nous clock is neither being input or output).
(3) As a trigger condition, it is required that data writing or
reading on data registers SD0–SD7 be performed prior to
writing "1" to SCTRG. (The internal circuit of the serial
interface is initiated through data writing/reading on
data registers SD0–SD7.) Supply trigger only once every
time the serial interface is placed in the RUN state.
Moreover, when the synchronous clock SCLK is external
clock, start to input the external clock after the trigger.
(1) The BZ and BZ signals may generate hazards in the
following cases:
– When the content of R43 register is changed, BZ and
BZ signals are switched ON or OFF.
– When the contents of buzzer frequency selection
registers (BZFQ0–BZFQ2) while the buzzer signal (BZ
and BZ) is being output.
(2) The 1-shot buzzer operates only when the regular buzzer
output is in the OFF (R43 = "0") state and writing to
BZSHOT becomes invalid in the ON (R43 = "1") state.
(1) Be sure to data writing/reading for external memory in
the order of low-order bits (D0–D3) then high-order bits
(D4–D7).
(2) Because of the write-only (W/O) function, the chip select
register (P20–P23) may not be re-written by logical arith-
metic instruction.
(1) The interrupt factor flag is set when the interrupt condi-
tions are established, regardless of the setting of the
interrupt mask register. Note, however, that the input
interrupt factor flags (IK0 and IK1) will be eliminated.
External memory access
Interrupt