| xPC Target | |
The DM6804 has one AM9513A chip with 5 counters.
The DM6804 PWM & ARM driver programs the AM9513A for PWM or disarmed signal generation (a square wave with fixed frequency and variable duty cycle). Additionally the driver allows to arm and disarm the counter by the second block input. For the corresponding counter channel, the PWM signal is output at the pin named OUT.
Scaling Input to Output
| Hardware Output |
Block Input Data Type |
Scaling |
| TTL |
Duty cycle: double Arm: double |
0 to 1 <0.5 disarmed >0.5 armed |
Driver Block Parameters
Counter -- From the list, choose 1, 2, 3, 4, or 5 to select which counter is used with this driver block. 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.
Relative output frequency -- Enter a value less than 1. The Relative output frequency is multiplied by the Frequency base to set the fixed output frequency of the PWM-signal.
For example, if the output frequency of a square wave has to be 17.5 kHz, then choose F2=500kHz as the Frequency Base and enter 0.175 as the Relative Output Frequency. 500kHz x 0.175 = 87.5 kHz
Level sequence of square wave -- From the list, choose either high-low or low-high.
high-low, the square wave period starts with the TTL high part followed by the TTL low part.
low-high, the square wave period starts with the TTL low part followed by the TTL high part.
In either case, the duty cycle entering the block defines the duration of the TTL high part.
Level when disarmed -- From the list, choose either high or low. The counter is automatically disarmed when the target application is not running. If the application is running, the second input port controls whether the counter is armed or disarmed. This parameter sets the TTL level when the counter is disarmed.
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)
Base address -- 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
| | DM6804 Counter PWM | DM6804 Counter FM | |