F U N C T I O N A L D E S C R I P T I O N
STKP - Stick Parity:
F o r c e s p a r i t y t o l o g i c 1 o r l o g i c 0 i f p a r i t y i s
enabled. See EPS, PEN, and figure 9.
EPS - Even Parity Select:
S e l e c t s e v e n o r o d d p a r i t y i f p a r i t y i s e n a b l e d .
See STKP, PEN, and figure 9.
PEN - Parity Enable:
E n a b l e s p a r i t y o n t r a n s m i s s i o n a n d v e r i f i c a t i o n
on reception. See EPS, STKP, and figure 9.
+--------------+---------+
| STKP EPS PEN | Parity |
+--------------+---------+
| x x 0 | None |
| 0 0 1 | Odd |
| 0 1 1 | Even |
| 1 0 1 | Logic 1 |
| 1 1 1 | Logic 0 |
+--------------+---------+
Figure 9. 16550 parity selections.
STB - Number of Stop Bits:
S e t s t h e n u m b e r o f s t o p b i t s t r a n s m i t t e d . S e e
WLSx and figure 10.
WLSx - Word Length Select:
D e t e r m i n e s t h e n u m b e r o f b i t s p e r t r a n s m i t t e d
word. See STB and figure 10.
+---------------+-------------+-----------+
| STB WLS1 WLS0 | Word length | Stop bits |
+---------------+-------------+-----------+
| 0 0 0 | 5 bits | 1 |
| 0 0 1 | 6 bits | 1 |
| 0 1 0 | 7 bits | 1 |
| 0 1 1 | 8 bits | 1 |
| 1 0 0 | 5 bits | 1½ |
| 1 0 1 | 6 bits | 2 |
| 1 1 0 | 7 bits | 2 |
| 1 1 1 | 8 bits | 2 |
+---------------+-------------+-----------+
Figure 10. Word length and stop bit selections.
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