AP513 ACROPACK
USER
’S MANUAL
Acromag, Inc. Tel: 248-295-0310
- 30 -
http://www.acromag.com
- 30 -
www.acromag.com
The closest actual divisor that is obtainable in the XR17V354 can be
calculated using the following formula:
Actual Divisor (decimal) = ROUND( (Calculated Divisor - TRUNC (Calculated
Divisor) )*16)/16 + TRUNC (Calculated Divisor),
DLM = TRUNC (Actual Divisor in hex) >> 8
DLL = TRUNC (Actual Divisor in hex) & 0xFF
DLD = ROUND ( (Calculated Divisor - TRUNC (Calculated Divisor) )*16)
In the formulas above, please note that: TRUNC (N) = Integer Part of N. For
example, TRUNC (5.6) = 5. ROUND (N) = N rounded towards the closest
integer. For example, ROUND (7.3) = 7 and ROUND (9.9) = 10.
Table 3.9 Typical Data Rates with
Internal 125MHz Clock at 16X
Sampling
Required
Output
Data Rate
Divisor for
16X Clock
(decimal)
Divisor
Obtainable in
XR17V354
DLM
Program
Value
(HEX)
DLL
Program
Value
(HEX)
DLD
Program
Value
(HEX)
Data
Error
Rate
(%)
9600
813.80
813 12/16
03
2D
D
0
19200
406.90
406 14/16
01
96
E
0.01
38400
203.45
203 7/16
00
CB
7
0.01
57600
135.63
135 10/16
00
87
A
0.01
115200
67.82
67 13/16
00
43
D
0.01
Note that there is a more extensive list of possible data rates in the Exar
datasheet.
3.4.3.2 DLD[7:4]
Table 3.10 DLD Register[7:4
]
DLD BIT
INTERRUPT ACTION
4
Not Used.
5
Multi-drop Mode:
0 = Normal mode.
1 = Enable Multi-drop mode.
6
XON/XOFF Parity Check:
0 = XON/XOFF characters are valid flow control characters
even if they have parity errors.
1 = XON/XOFF characters are not valid flow control
characters if they have parity errors.
7
Not Used.