s3c72m9 Samsung Semiconductor, Inc., s3c72m9 Datasheet - Page 276

• Manufacturer Part Number: s3c72m9
• Description: The S3c72m5/s3c72m7/s3c72m9 Single-chip Cmos Microcontroller Has Been Designed For High Performance Using Samsung S
• Manufacturer: Samsung Semiconductor, Inc.

TIMERS and TIMER/COUNTERS
TC1 CLOCK FREQUENCY OUTPUT
Using timer/counter 1, a modifiable clock frequency can be output to the TC1 clock output pin, TCLO1. To select the
clock frequency, load the appropriate values to the TC1 mode register, TMOD1A. The clock interval is selected by
loading the desired reference value into the 16-bit reference register TREF1. To enable the output to the TCLO1 pin
at I/O port 3.1, the following conditions must be met:
— TC1 output enable flag TOE1 must be set to "1".
— I/O mode flag for P3.1 (PM3.1) must be set to output mode ("1").
— P3.1 output latch must be cleared to "0".
In summary, the operational sequence required to output a TC1-generated clock signal to the TCLO1 pin is as
follows:
1. Load your reference value to TREF1.
2. Set the internal clock frequency in TMOD1A.
3. Initiate TC1 clock output to TCLO1 (TMOD1A.2 = "1").
4. Set port 3.1 mode flag (PM3.1) to "1".
5. Clear the P3.1 output latch.
6. Set TOE1 flag to "1".
Each time TCNT1 overflows and an interrupt request is generated, the state of the output latch TOL1 is inverted and
the TC1-generated clock signal is output to the TCLO1 pin.
F
Output a 30 ms pulse width signal to the TCLO1 pin:
11-28
PROGRAMMING TIP — TC1 Signal Output to the TCLO1 Pin
BITS
SMB
LD
LD
LD
LD
LD
LD
LD
LD
BITR
BITS
EMB
15
EA,#79H
TREF1A,EA
EA,#00H
TREF1B,EA
EA,#0CCH
TMOD1A,EA
EA,#02H
PMG2,EA
P3.1
TOE1
; P3.1
; P3.1 clear
S3C72M5/C72M7/C72M9/P72M9 (Preliminary Spec)
output mode