B-26, Figure b-26, Timer control/status register (tcsr) – Motorola DSP56301 User Manual

Page 350: Timers

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Programming Sheets

B

-38

DSP56301 User’s Manual

Figure B-26. Timer Control/Status Register (TCSR)

Application:

Date:

Programmer:

Sheet 2 of 3

15 14 13 12 11 10

9

8

7

6

5

4

3

2

1

0

TC3

TC1

TC0

TCIE TQIE

TE

19 18 17 16

23 22 21 20

TCF

TC2

PCE

DO

DI

DIR

TOF

TRM

INV

Timers

*

0

*

0

*

0

*

0

*

0

*

0

*

0

*

0

*

0

Timer Enable Bit 0
0 = Timer Disabled
1 = Timer Enabled

Timer Overflow Interrupt Enable Bit 1
0 = Overflow Interrupts Disabled
1 = Overflow Interrupts Enabled

Inverter Bit 8
0 = 0- to-1 transitions on TIO input increment the counter,
or high pulse width measured, or high pulse output on TIO

1 = 1-to-0 transitions on TIO input increment the counter,
or low pulse width measured, or low pulse output on TIO

Timer Compare Interrupt Enable Bit 2
0 = Compare Interrupts Disabled
1 = Compare Interrupts Enabled

Timer Control/Status Register

TCSR0:$FFFF8F Read/Write
TCSR1:$FFFF8B Read/Write
TCSR2:$FFFF87 Read/Write

Reset = $000000

*

= Reserved, Program as 0

Timer Reload Mode Bit 9

1 = Timer is reloaded when

selected condition occurs

0 = Timer operates as a free

running counter

Timer Overflow Flag Bit 20
0 = “1” has been written to TCSR(TOF),

or timer Overflow interrupt serviced

1 = Counter wraparound has occurred

Direction Bit 11
0 = TIO pin is input
1 = TIO pin is output

Data Output Bit 13
0 = Zero written to TIO pin
1 = One written to TIO pin

Data Input Bit 12
0 = Zero read on TIO pin
1 = One read on TIO pin

Timer Compare Flag Bit 21
0 = “1” has been written to TCSR(TCF),

or timer compare interrupt serviced

1 = Timer Compare has occurred

Prescaled Clock Enable Bit 15
0 = Clock source is CLK/2 or TIO
1 = Clock source is prescaler output

Timer Control Bits 4–7 (TC[3–0])

TC (3:0)

TIO

Clock

Mode

0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111

GPIO

Output
Output

Input
Input
Input
Input

Output

Output
Output





Internal
Internal
Internal

External

Internal
Internal
Internal
Internal

Internal
Internal





Timer
Timer Pulse
Timer Toggle
Event Counter
Input Width
Input Period
Capture
Pulse Width Modulation
Reserved
Watchdog Pulse
Watchdog Toggle
Reserved
Reserved
Reserved
Reserved
Reserved

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