SAA7348GP Datasheet, PDF (37/60 Pages) NXP Semiconductors – All Compact Disc Engine ACE

Philips Semiconductors
All Compact Disc Engine (ACE)
Preliminary specification
SAA7348GP
8.1.15 DIV17 REGISTER (address 0X9FH)
This register can be used to generate the serial communication baud rate. If this method is chosen, the baud rate will be
62259 × P. The 5 LSBs of DIV17 hold the value of P. The 2 MSBs connect this baud rate generator to UART 1 or UART 2
(see Table 28). The register is byte addressable; R/W.
Table 28 Baud rate to UART connection
BIT 7
0
0
1
1
BIT 6
0
1
0
1
DESCRIPTION
baud rate generator not selected
select baud rate generator only for UART1
select baud rate generator only for UART2
select baud rate generator for UART1 and UART2
Of course in ACE it is still possible to use timers 1 and 2 to generate the baud rate. Table 29 provides an overview of
how various baud rates can be generated using timer 1, timer 2, and DIV17.
Table 29 Baud rate selection, timer based; note 1
BAUD RATE
kBAUD
1 411.20
996.14
529.20
498.07
373.55
264.60
249.04
186.78
124.52
88.20
66.15
62.26
44.10
33.08
9.80
µPCLK
(MHz)
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
16.9344
MODE
0
X
2
X
X
2
X
X
X
1
1
X
1
1
1
Note
1. X = don’t care.
SMOD
X
1
1
1
1
0
1
1
1
1
X
1
0
X
1
RELOAD
TIMER 1
X
X
X
X
X
X
X
X
X
0XFF
X
X
0XFF
X
0XF7
RELOAD
TIMER 2
X
X
X
X
X
X
X
X
X
X
0XFFF0
X
X
0XFFE8
X
DIV17
(ACE)
X
16
X
8
6
X
4
3
2
X
X
1
X
X
X
1997 Jul 11
37