upd78f0124hgba1-8et-a Renesas Electronics Corporation., upd78f0124hgba1-8et-a Datasheet - Page 224

• Manufacturer Part Number: upd78f0124hgba1-8et-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

11.4 Clock Output Controller Operations
224
(2) Port mode register 14 (PM14)
The clock pulse is output as the following procedure.
<1> Select the clock pulse output frequency with bits 0 to 3 (CCS0 to CCS3) of the clock output selection register
<2> Set bit 4 (CLOE) of CKS to 1 to enable clock output.
Remark
This register sets port 14 input/output in 1-bit units.
When using the P140/INTP6/PCL pin for clock output, set PM140 and the output latch of P140 to 0.
PM14 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets PM14 to FFH.
(CKS) (clock pulse output in disabled status).
Clock output
The clock output controller is designed not to output pulses with a small width during output
enable/disable switching of the clock output. As shown in Figure 11-4, be sure to start output from the
low period of the clock (marked with * in the figure). When stopping output, do so after securing high
level of the clock.
CLOE
Address: FF2EH
Symbol
PM14
PM140
Figure 11-4. Remote Control Output Application Example
*
7
1
0
1
Figure 11-3. Format of Port Mode Register 14 (PM14)
After reset: FFH
CHAPTER 11 CLOCK OUTPUT CONTROLLER
Output mode (output buffer on)
Input mode (output buffer off)
6
1
User’s Manual U16962EJ3V0UD
5
1
R/W
P140 pin I/O mode selection
4
1
3
1
*
2
1
1
1
PM140
0