Epson S1C63558 - Manual (Page 164)

154 EPSON S1C63558 TECHNICAL AMANUAL
CHAPTER 5: SUMMARY OF NOTES
Output port
(1) When using an output port (R00–R03, R10–R13) for special output, fix the corresponding data register
(R00–R03, R10–R13) at "1" and the high impedance control register (R00HIZ–R03HIZ, R10HIZ–
R13HIZ) at "0" (data output).
Be aware that the output terminal is fixed at a low (V
SS ) level the same as the DC output if "0" is
written to the data registers when the special output has been selected.
Be aware that the output terminal shifts into high impedance status when "1" is written to the high
impedance control register.
(2) A hazard may occur when the TOUT, FOUT , BZ or XBZ signal is turned ON and OFF.
(3) When f OSC3 is selected for the FOUT signal frequency, it is necessary to control the OSC3 oscillation
circuit before output.
Refer to Section 4.3, "Oscillation Circuit", for the control and notes.
I/O port
(1) When in the input mode, I/O ports are changed from low to high by pull-up resistor, the rise of the
waveform is delayed on account of the time constant of the pull-up resistor and input gate capaci-
tance. Hence, when fetching input ports, set an appropriate wait time.
Particular care needs to be taken of the key scan during key matrix configuration.
Make this waiting time the amount of time or more calculated by the following expression.
10
×
C
×
R
C: terminal capacitance 5 pF + parasitic capacitance ? pF
R: pull-up resistance 330 k
Ω
(2) When special output (CL, FR) has been selected, a hazard may occur when the signal is turned ON or
OFF.
LCD driver
(1) When a program that access no memory mounted area (F050H–F0FFH, F150H–F1FFH, F201H, F203H,
· · ·, F24FH) is made, the operation is not guaranteed.
(2) Because at initial reset, the contents of display memory and LC3–LC0 (LCD contrast) are undefined,
there is need to initialize by the software. Furthermore, take care of the registers LPWR and ALOFF
because these are set so that the display goes OFF.
(3) The COM8–COM16 terminals can be set as the SEG47–SEG40 terminals by mask option. In this case,
only 1/8 drive duty can be selected, so a dot matrix type LCD with a maximum of 384 (48
×
8) dots
can be driven. When 48 segments
×
8 commons is selected, COM terminals change to SEG terminals
as follows:
COM16
→
SEG40 COM15
→
SEG41 COM14
→
SEG42 COM13
→
SEG43 COM12
→
SEG44
COM11
→
SEG45 COM10
→
SEG46 COM9
→
SEG47 COM8
→
SEG47
This option is valid on the PRC board, however, the SEG47–SEG40 terminals are separately provided.
Therefore, be aware that the COM8–COM16 terminals cannot be changed to the SEG47–SEG40.
Clock timer
Be sure to read timer data in the order of low-order data (TM0–TM3) then high-order data (TM4–TM7).
Stopwatch timer
When data of the counter is read at run mode, perform the reading after suspending the counter once
and then set SWRUN to "1" again. Moreover, it is required that the suspension period not exceed 976
µsec (1/4 cycle of 256 Hz).
Programmable timer
(1) When reading counter data, be sure to read the low-order 4 bits (PTD00–PTD03, PTD10–PTD13) first.
Furthermore, the high-order 4 bits (PTD04–PTD07, PTD14–PTD17) should be read within 0.73 msec
(when f
OSC1 is 32.768 kHz) of reading the low-order 4 bits (PTD00–PTD03, PTD10–PTD13).