參數資料
型號: SAA5297A
廠商: NXP Semiconductors N.V.
英文描述: Economy teletext and TV microcontrollers
中文描述: 經濟圖文電視和電視微控制器
文件頁數: 12/68頁
文件大?。?/td> 612K
代理商: SAA5297A
1997 Jul 07
12
Philips Semiconductors
Preliminary specification
Economy teletext and TV microcontrollers
SAA5x9x family
7.3.6
14-
BIT
PWM DAC
One 14-bit DAC is available to allow direct control of
analog sections of the television. The 14-bit PWM is
controlled using Special Function Registers TDACL and
TDACH.
The output of the TPWM is a pulse of period 42.66
μ
s. The
7 most significant bits, TDACH.TD13
(MSB) to TDACH.TD8 and TDACL.TD7, alter the pulse
width between 0 and 42.33
μ
s, in much the same way as
in the 6-bit PWMs. The 7 least significant bits, TDACL.TD6
to TDACL.TD0 (LSB), extend certain pulses by a further
0.33
μ
s, e.g. if the 7 least significant bits are given the
value 01H, then 1 in 128 cycles is extended. If the 7 least
significant bits are given the value 02H, then
2 in 128 cycles is extended, and so forth.
The TPWM will not start to output a new value until after
writing a value to TDACH. Therefore, if the value is to be
changed, TDACL should be written to before TDACH.
7.3.6.1
TPWM High Byte Register (TDACH)
Table 5
TPWM High Byte Register (SFR address D3H)
Table 6
Description of TDACH bits
7.3.6.2
TPWM Low Byte Register (TDACL)
Table 7
TPWM Low Byte Register (SFR address D2H)
Table 8
Description of TDACL bits
7
6
5
4
3
2
1
0
PWE
TD13
TD12
TD11
TD10
TD9
TD8
BIT
SYMBOL
DESCRIPTION
7
PWE
If PWE is set to a logic 1, the TPWM is active and controls port line P2.0. If PWE is set
to a logic 0, the port pin is controlled by the corresponding bit in the port SFR.
Not used.
These 6-bits along with bit TD7 in the TDACL register control the pulse width period.
TD13 is the most significant bit.
6
5
4
3
2
1
0
TD13
TD12
TD11
TD10
TD9
TD8
7
6
5
4
3
2
1
0
TD7
TD6
TD5
TD4
TD3
TD2
TD1
TD0
BIT
SYMBOL
DESCRIPTION
7
TD7
This bit is used with bits TD13 to TD8 in the TDACH register to control the pulse width
period.
These 7-bits extend certain pulses by a further 0.33
μ
s.
6 to 0
TD6 to TD0
相關PDF資料
PDF描述
SAA5297AH Economy teletext and TV microcontrollers
SAA5297APS Economy teletext and TV microcontrollers
SAA5297H Economy teletext and TV microcontrollers
SAA5297PS Economy teletext and TV microcontrollers
SAA5491 Economy teletext and TV microcontrollers
相關代理商/技術參數
參數描述
SAA5297AH 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Economy teletext and TV microcontrollers
SAA5297APS 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Economy teletext and TV microcontrollers
SAA5297H 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Economy teletext and TV microcontrollers
SAA5297PS 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Economy teletext and TV microcontrollers
SAA5355 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Single-chip colour CRT controller FTFROM