B-21 Timer Control/Status Register (Tcsr) - Motorola DSP56303 User Manual

Programming Sheets
Application:
Timers
Timer Reload Mode Bit 9
0 = Timer operates as a free
running counter
1 = Timer is reloaded when
selected condition occurs
Direction Bit 11
0 = TIO pin is input
1 = TIO pin is output
Data Input Bit 12
0 = Zero read on TIO pin
1 = One read on TIO pin
Data Output Bit 13
0 = Zero written to TIO pin
1 = One written to TIO pin
Prescaled Clock Enable Bit 15
0 = Clock source is CLK/2 or TIO
1 = Clock source is prescaler output
Timer Compare Flag Bit 21
0 = "1" has been written to TCSR(TCF),
or timer compare interrupt serviced
1 = Timer Compare has occurred
Timer Overflow Flag Bit 20
0 = "1" has been written to TCSR(TOF),
or timer Overflow interrupt serviced
1 = Counter wraparound has occurred
23 22 21 20 19 18 17 16
* * TCF TOF *
0 0
Timer Control/Status Register TCSR0:$FFFF8F Read/Write
Reset = $000000
Figure B-21. Timer Control/Status Register (TCSR)
B-32
Inverter Bit 8
0 = 0- to-1 transitions on TIO input increment the counter,
or high pulse width measured, or high pulse output on TIO
1 = 1-to-0 transitions on TIO input increment the counter,
or low pulse width measured, or low pulse output on TIO
15 14 13 12 11 10 9
* * * PCE * DO
0 0 0 0 0
TCSR1:$FFFF8B Read/Write
TCSR2:$FFFF87 Read/Write
DSP56303 User's Manual
Date:
Programmer:
Timer Control Bits 4–7 (TC[3–0])
TC (3:0) TIO
0000 GPIO
0001 Output
0010 Output
0011 Input
0100 Input
0101 Input
0110 Input
0111 Output
1000 –
1001 Output
1010 Output
1011 –
1100 –
1101 –
1110 –
1111 –
Timer Overflow Interrupt Enable Bit 1
0 = Overflow Interrupts Disabled
1 = Overflow Interrupts Enabled
Timer Compare Interrupt Enable Bit 2
0 = Compare Interrupts Disabled
1 = Compare Interrupts Enabled
8 7
DI DIR * TRM INV TC3 TC2
0
*
Sheet 2 of 3
Clock Mode
Internal Timer
Internal Timer Pulse
Internal Timer Toggle
External Event Counter
Internal Input Width
Internal Input Period
Internal Capture
Internal Pulse Width Modulation
– Reserved
Internal Watchdog Pulse
Internal Watchdog Toggle
– Reserved
– Reserved
– Reserved
– Reserved
– Reserved
Timer Enable Bit 0
0 = Timer Disabled
1 = Timer Enabled
6 5 4 3 2 1
TC1 TC0 * TCIE TQIE TE
0
= Reserved, Program as 0
0