MX10EXAQC 查看數據表（PDF） - Macronix International

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MX10EXAQC

XA 16-bit Microcontroller Family 64K Flash/2K RAM, Watchdog, 2UARTs

Macronix International 

MX10EXA

T2CON Address:418 MSB

Bit Addressable

Reset Value:00H

TF2

EXF2 RCLK0 TCLK0 EXEN2 TR2

LSB

C/T2 CP/RL2

BIT

T2CON.7

T2CON.6

T2CON.5

T2CON.4

T2CON.3

T2CON.2

T2CON.1

T2CON.0

SYMBOL

TF2

EXF2

RCLK0

TCLK0

EXEN2

TR2

C/T2

CP/RL2

FUNCTION

Timer 2 overflow flag. Set by hardware on Timer/Counter overflow. Must be cleared

by software. TF2 will not be set when RCLK0, RCLK1, TCLK0, TCLK1 or T2OE=1.

Timer 2 external flag is set when a capture or reload occurs due to a negative

transition on T2EX (and EXEN2 is set). This flag will cause a Timer 2 interrupt when

this interrupt is enabled. EXF2 is cleared by software.

Receive Clock Flag.

Transmit Clock Flag. RCLK0 and TCLK0 are used to select Timer 2 overflow rate as

a clock source for UART0 instead of Timer T1.

Timer 2 external enable bit allows a capture or reload to occur due to a negative

transition on T2EX.

Start = 1/Stop=0 control for Timer 2.

Timer or counter select.

0 = Internal timer

1 = External event counter (falling edge triggered)

Capture/Reload flag.

If CP/RL2 & EXEN2 = 1 captures will occur on negative transitions of T2EX.

If CP/RL2 = 0, EXEN2 = 1 auto reloads occur with either Timer 2 overflows or

negative transitions at T2EX.

If RCLK or TCLK = 1 the timer is set to auto reload on Timer 2 overflow, this bit has

no effect.

Figure 8. Timer/Counter 2 Control (T2CON) Register

New Timer-Overflow Toggle Output

In the XA, the timer module now has two outputs, which

toggle on overflow from the individual timers. The same

device pins that are used for the T0 and T1 count inputs

are also used for the new overflow outputs. An SFR bit

(TnOE in the TSTAT register) is associated with each

counter and indicates whether Port-SFR data or the over-

flow signal is output to the pin. These outputs could be

used in applications for generating variable duty cycle

PWM outputs (changing the auto-reload register values).

Also variable frequency (Osc/8 to Osc/8,388,608) out-

puts could be achieved by adjusting the prescaler along

with the auto-reload register values. With a 30.0MHz os-

cillator, this range would be 3.58Hz to 3.75MHz.

Timer T2

Timer 2 in the XA is a 16-bit Timer/Counter which can

operate as either a timer or as an event counter. This is

selected by C/T2 in the special function register T2CON.

Upon timer T2 overflow/underflow, the TF2 flag is set,

which may be used to generate an interrupt. It can be

operated in one of three operating modes: auto-reload

(up or down counting), capture, or as the baud rate gen-

erator (for either or both UARTs via SFRs T2MOD and

T2CON). These modes are shown in Table 4.

Capture Mode

In the capture mode there are two options which are se-

lected by bit EXEN2 in T2CON. If EXEN2 = 0, then timer

2 is a 16-bit timer or counter, which upon overflowing

sets bit TF2, the timer 2 overflow bit. This will cause an

interrupt when the timer 2 interrupt is enabled.

If EXEN2 = 1, then Timer 2 still does the above, but with

the added feature that a 1-to-0 transition at external in-

put T2EX causes the current value in the Timer 2 regis-

ters, TL2 and TH2, to be captured into registers RCAP2L

and RCAP2H, respectively. In addition, the transition at

T2EX causes bit EXF2 in T2CON to be set. This will

cause an interrupt in the same fashion as TF2 when the

Timer 2 interrupt is enabled. The capture mode is illus-

trated in Figure 11.

P/N:PM0625 Specifications subject to change without notice, contact your sales representatives for the most update information. REV. 1.0, JUL. 01, 2005

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