17 Parallel Interface (PIO)
S1C17F13 TeChniCal Manual
Seiko epson Corporation
17-5
(Rev. 1.0)
Control Registers
17.5
PiO Clock Control Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
PIOCLK
15–9 –
0x00
–
R
–
8
DBRUN
0
H0
R/W
7–6 –
0x0
–
R
5–4 CLKDIV[1:0]
0x0
H0
R/W
3–2 –
0x0
–
R
1–0 CLKSRC[1:0]
0x0
H0
R/W
Bits 15–9 Reserved
Bit 8
DBRun
This bit sets whether the PIO operating clock is supplied in DEBUG mode or not.
1 (R/W): Clock supplied in DEBUG mode
0 (R/W): No clock supplied in DEBUG mode
Bits 7–6
Reserved
Bits 5–4
ClKDiV[1:0]
These bits select the division ratio of the PIO operating clock.
Bits 3–2
Reserved
Bits 1–0
ClKSRC[1:0]
These bits select the clock source of PIO.
5.1 Clock Source and Division Ratio Settings
Table 17.
PIOCLK.
CLKDIV[1:0] bits
PIOCLK.CLKSRC[1:0] bits
0x0
0x1
0x2
0x3
OSC3B
OSC1
OSC3A
EXOSC
0x3
1/8
1/8
1/8
1/1
0x2
1/4
1/4
1/4
0x1
1/2
1/2
1/2
0x0
1/1
1/1
1/1
(Note) The oscillation circuits/external input that are not supported in this IC cannot be
selected as the clock source.
Note: The PIOCLK register settings can be altered only when the PIOCTL.MODEN bit = 0.
PiO Mode Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
PIOMOD
15–8 –
0x00
–
R
–
7–2 –
0x00
–
R
1
PUL
0
H0
R/W
0
GPIOMD
0
H0
R/W
Bits 15–2 Reserved
Bit 1
Pul
This bit enables pull-up of the PIO pins.
1 (R/W): Enable pull-up
0 (R/W): Disable pull-up
Bit 0
GPiOMD
This bit sets PIO to GPIO mode.
1 (R/W): GPIO mode
0 (R/W): SRAM mode