Programmable Timer Module

The D6840 is a programmable timer module compatible with 6840 industry standard. This IP core is designed for using as peripheral device for D68xx processors or as separate module in applications where features of 6840 timer are useful. The D6840 has three separate 16-bit timers, with separate control and common status registers. The timers may be used for square wave generation with duty cycle regulation. Signal may be generated as continuous wave or single-shot mode. There is also capability for using D6840 module for frequency or pulse width measurement and comparison. The D6840 has interrupt which is useful in controlling module by CPU.
The D6840 is a technology independent design that can be implemented in a variety of process technologies.

Figure below shows typical connection of the D6840 to microcontroller.

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Compatible with 6840 industry standard Three separate timers Two operation modes Wave synthesis Wave measurement Two generation modes Continuous Single shot Gating system for each clock input Separate timer outputs Prescaler mode for timer3 input clock External clock or E clock used for timer decrement Interrupt generation Split bus for input and output data Fully synthesizable Static synchronous design and no internal tri-states		External module for D68xx processors Gated wave generation Pulse width modulation Frequency measurement and comparison Pulse width measurement and comparison

Pin	Type	Description
e	input	E clock input
reset	input	Global reset
clk	input	Global clock
g3	input	Timer 3 clock gate input
c3	input	Timer 3 external clock input
datai (7:0)	input	Data bus input
rs (2:0)	input	Register select
rw	input	Read/write control
cs0	input	Chip select 0
cs1	input	Chip select 1
c1	input	Timer 1 external clock input
g1	input	Timer 1 clock gate input
c2	input	Timer 2 external clock input
g2	input	Timer 2 clock gate input
o3	output	Timer 3 output
irq	output	Interrupt request
datao (7:0)	output	Data bus output
o1	output	Timer 1 output
o2	output	Timer 2 output