III PERIPHERAL BLOCK:
CFP14: P14 function selection (D4) / P1 function select register (0x402D4)
Selects the pin function of the P14 I/O port.
Write "1": OSC1 clock output pin
Write "0": I/O port pin
Read: Invalid
The P14 pin is set for OSC1 clock output (FOSC1) by writing "1" to CFP14.
When this pin is used as the FOSC1 output pin, also set IOC14 (D4/0x402D6 <P1 I/O control register>) to "1" (output).
At cold start, CFP14 is set to "0" (I/O port pin). At hot start, CFP14 retains its status from before the initial reset.
CFEX0: P12, P14 extended function (D0) / Port function extension register (0x402DF)
Sets whether the function of the P14 pin is to be extended.
Write "1": DCLK output pin
Write "0": P14/FOSC1 output pin
Read: Invalid
When CFEX0 is set to "1", the P14 pin functions as a debug clock DCLK output pin. When CFEX0 = "0", the CFP14 register becomes effective, so the settings of this register determine whether the P14 pin functions as an P14 I/O port or a FOSC1 output pin.
At cold start, CFEX0 is set to "1" (DCLK output pin). At hot start, CFEX0 retains its state from prior to the initial reset.
Programming Notes
(1)Immediately after the
(2)The oscillation circuit used for the CPU operating clock cannot be turned off.
(3)The CPU operating clock can only be switched over when both the OSC3 and OSC1 oscillation circuits are on. Furthermore, when turning off an oscillation circuit that has become unnecessary as a result of the CPU operating clock switchover, be sure to use separate instructions for switchover and oscillation turnoff. If these two operations are processed simultaneously using one instruction, the CPU may operate erratically.
(4)If the
(5)If the OSC3 clock is unnecessary, use the OSC1 clock to operate the CPU and turn the
(6)When the P14/FOSC1/DCLK pin is used as the FOSC1 output pin, set IOC14 (D4/0x402D6) to "1" (output) in addition to the CFP14 (D4/0x402D4) and CFEX0 (D0/0x402DF) settings.
EPSON | S1C33210 FUNCTION PART |