20-668-0024 Rabbit Semiconductor, 20-668-0024 Datasheet - Page 135

• Manufacturer Part Number: 20-668-0024
• Description: IC CPU RABBIT4000 128-LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0024

• Processor Type: Rabbit 4000 8-bit
• Speed: 60MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: 20-668-0022; 316-1078

15.3 Operation
The following steps explain how to set up a Timer C timer.
1. Select perclk/2, perclk/16, or countdown timer A1 in TCCR.
2. Load the desired upper limit for the counter into TCDLR and TCDHR. The overall
3. Load the desired set and reset values for the Timer C outputs into the set and reset
4. If you intend to use DMA control of Timer C, use TCBAR to access the Timer C
5. Enable the desired output pins for Timer C by writing to the appropriate parallel port
6. Enable Timer C by writing a 1 to bit 0 of TCCSR.
15.3.1 Handling Interrupts
The following steps explain how an interrupt is used.
1. Write the vector to the interrupt service routine to the internal interrupt table.
2. Configure TCCR to select the interrupt priority (note that interrupts will be enabled
The interrupt request is cleared by reading from TCCSR.
15.3.2 Example ISR
A sample interrupt handler is shown below.
Chapter 15 Timer C
clock count per Timer C cycle will be the value loaded into the divider registers plus
one.
registers (TCSxLR, TCSxHR, TCRxLR, and TCRxHR).
register pointed to by TCBPR.
function and alternate output registers.
once this value is set).
timerC_isr::
push af
ioi ld a, (TCCSR)
; handle all interrupts flagged in TCCSR here
pop af
ipres
ret
; save used registers
; clear the interrupt request and get status
; restore used registers
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