Filter
Top Products
5-41
STANDARD AND PTS INTERRUPTS
PTS Serial I/O Mode Control Block 2
(8XC196MC, MD)
The PTS control block 2 contains pointers to both the port register (PORTREG) and the data register
(DATA). It also contains a 16-bit value that is used to calculate the sample time for asynchronous
receptions when majority sampling is selected (SAMPTIME), a control register (PTSCON1), and a 16-
bit value that is used to select the port signal that functions as the TXD or RXD signal (PORTMASK).
7 0
Unused
0 0 0 0 0 0 0 0
7 0
SAMPTIME
Sample Time Value
15 8
DATA (H)
Data Register (high byte)
7 0
DATA (L)
Data Register (low byte)
7 0
PTSCON1 (Synch)
0 0 0 0 0 0 TRC 0
7 0
PTSCON1 (Asynch)
0 RPAR PEN 0 0 0 FE TPAR
7 0
PORTMASK
Port Mask Register
15 0
PORTREG (H)
Port Address Pointer (high byte)
7 0
PORTREG (L)
Port Address Pointer (low byte)
Register Location Function
SAMPTIME PTSCB2 + 6 Sample Time Value
This register controls the time between samples during
asynchronous receive mode when majority sampling is selected.
Use the following formula to calulate the value to load into the
SAMPTIME register.
where:
Sample_time is an integer, 1–31, that is loaded into the
SAMPTIME register
T
SAM
is the desired time between samples, in µs
F
XTAL1
is the input frequency on XTAL1, in MHz
Figure 5-20. PTS Control Block 2 – Serial I/O Mode
Sample_time
T
SAM
F
XTAL1
×
2
-------------------------------------------
9–=