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5-37
STANDARD AND PTS INTERRUPTS
5.6.5.3 A/D Scan Mode Example 2
Table 5-11 sets up a series of ten PTS cycles, each of which reads a single A/D channel and stores
the result in a single location (3002H). The UPDT bit (PTSCON.3) is cleared so that original con-
tents of PTSPTR1 are restored after the cycle. The command/data table is shown in Table 5-10.
Software starts a conversion on channel x. When the conversion is finished and the A/D conver-
sion complete interrupt is generated, the A/D scan mode routine begins. The PTS reads the com-
mand in location 3000H and stores it in a temporary location. Then it increments PTSPTR1 twice
and stores the value of the AD_RESULT register in location 3002H. The final step is to copy the
conversion command from the temporary location to the AD_COMMAND register. The CPU
could process or move the conversion results data from the table before the next conversion com-
pletes and a new PTS cycle begins. When the next cycle begins, PTSPTR1 again points to 3000H
and the repeats the events of the first cycle. The value of the AD_RESULT register is written to
location 3002H and the command at location 3000H is re-executed.
5.6.6 Serial I/O Modes
The 8XC196MH has a two-channel serial I/O port. The 8XC196MC and MD have no serial I/O
ports, but the serial I/O modes of the PTS provide a software serial I/O channel for both synchro-
nous and asynchronous transfers and receptions. There are four basic modes of operation: syn-
chronous transmit, synchronous receive, asynchronous transmit, and asynchronous receive. A
standard I/O port signal is configured to function as either the transmit data (TXD) or receive data
(RXD) signal and an EPA channel sets the baud rate. You may configure any port 2 signal (MC
and MD) or P7.3:0 (MD) as TXD or RXD. In the synchronous modes, an EPA channel can either
generate the serial clock (SCK) signal or input an external clock signal. Up to 16 bits may be
Table 5-10. Command/Data Table (Example 2)
Address Contents
3002H AD_RESULT for ACH
x
3000H Unused AD_COMMAND for ACH
x
Table 5-11. A/D Scan Mode PTSCB (Example 2)
Unused
Unused
PTSPTR2 (H) = 1FH
PTSPTR2 (L) = AAH
PTSPTR1 (H) = 30H
PTSPTR1 (L) = 00H
PTSCON = C3H (Mode = 110, UPDT = 0)
PTSCOUNT = 0AH