p87c770 ETC-unknow, p87c770 Datasheet - Page 33

• Manufacturer Part Number: p87c770
• Description: Microcontrollers Ntsc With On-screen Display Closed Caption
• Manufacturer: ETC-unknow

Philips Semiconductors
16.1
Table 40 AFT Control Register (SFR address EAH)
Table 41 Description of AFCON bits
Table 42 Selection of AFT channel
1999 Jun 11
Microcontrollers for NTSC TVs with On-Screen
Display (OSD) and Closed Caption (CC)
AFTH1
BIT
7
7
6
5
4
3
2
1
0
0
0
1
1
AFT Control Register (AFCON)
SYMBOL
AFTH0
AFTH1
AFTH1
AFTH0
AFTL3
AFTL2
AFTL1
AFTL0
AFTC
6
0
1
0
1
Reserved.
AFT channel selection. These two bits are used to select the AFT channel; see
Table 42.
AFT reference voltage level selection. These four bits are used to select the analog
output voltage (V
AFT compare result. If AFTC = 0; the AFT input voltage is lower than the reference
voltage. If AFTC = 1; the AFC input voltage is higher than the reference voltage.
AFT0
AFT1
AFT2
illegal code
V
ref
AFTH0
=
5
V
--------- -
16
DD
DAC value
ref
AFTL3
) of the 4-bit DAC. V
4
+
33
1
CHANNEL SELECTED
AFTL2
3
DESCRIPTION
ref
is calculated as shown in the equation below:
AFTL1
2
P8xCx70 family
AFTL0
1
Product specification
AFTC
0