Specifications

DM6804
19
second block input. If a value 0 is asserted, the counter is disarmed. If a value
1 is asserted, the counter gets armed.
Sample Time - Enter the base sample time or a multiple of the base sample
time. The sample time indicates the update rate of registration on the input
(Duty Cycle)
BaseAddress - Enter the base address of the board. This entry must
corresponds to the DIP-switch settings on the board. For example, if the base
address is 300 (hexadecimal), enter
0x300
DM6804 PWM Capture
This block programs the AMD9513A for capturing PWM signals by using two
counters. One counter measures the cycle duration, and the other counter
measures the duration the signal is high.
There are two outputs. One output is the relative frequency compared to the
base frequency. The other output is the duty cycle. To get the actual frequency,
multiply the base frequency by the relative frequency.
Scaling Input to Output
Driver Block Parameters
Counter - From the list, choose 1&2, 2&3, 3&4, 4&5. This selects which two
counters the driver block uses to determine the PWM. In each case, one block
is needed for each counter.
Frequency Base - From the list, choose F1=5MHz, F2=500kHz, F3=50kHz,
F4=5kHz, or F5=500Hz to set the base frequency. The XTAL frequency is
assumed to be 1MHz, therefore the jumper on the DM6804 has to be in position
1MHz not 5MHz.
Sample Time - Enter the base sample time or a multiple of the base sample
time. The sample time indicates the update rate of registration on the input
(Duty Cycle)
Hardware Output Block Input Data Type Scaling
TTL double 0 to 1