saa5647hl NXP Semiconductors, saa5647hl Datasheet - Page 12

• Manufacturer Part Number: saa5647hl
• Description: Saa56xx Enhanced Tv Microcontrollers With On-screen Display Osd
• Manufacturer: NXP Semiconductors

Philips Semiconductors
8.3
Figure 6 shows the internal Data RAM is organised into
two areas: Data memory and the Special Function
Registers (SFRs).
8.4
The Data memory (see Fig.6) is 256
address range 00H to FFH when using indirect addressing
and 00H to 7FH when using direct addressing. The SFRs
occupy the address range 80H to FFH and are accessible
using direct addressing only.
The lower 128 bytes of Data memory are mapped as
shown in Fig.7. The lowest 32 bytes are grouped into four
banks of eight registers selectable via SFR PSW
2004 Sep 03
handbook, halfpage
Enhanced TV microcontrollers with
On-Screen Display (OSD)
RAM organisation
Data memory
upper 128 bytes
lower 128 bytes
Fig.6 Internal Data memory.
FFH
80H
7FH
00H
and indirect
addressing
addressing
accessible
accessible
MEMORY
by indirect
by direct
DATA
only
8 bits and occupies
REGISTERS
FUNCTION
addressing
accessible
SPECIAL
by direct
only
MBK956
12
bits <4:3> (RS1/RS0; see Table 3), the next 16 bytes
above the register banks form a block of bit addressable
memory space.
The upper 128 bytes are not allocated for any special area
or functions.
Table 3 Bank selection
handbook, halfpage
11 = BANK 3
10 = BANK 2
01 = BANK 1
00 = BANK 0
bits in PSW
bank select
RS1
0
0
1
1
Fig.7 Lower 128 bytes of internal RAM.
7FH
2FH
20H
1FH
18H
17H
10H
0FH
08H
07H
00H
RS0
0
1
0
1
GSA060
Product specification
bit-addressable
space
(bit addresses
00H to 7FH)
4 banks of
8 registers
(R0 to R7)
SAA56xx
Bank 0
Bank 1
Bank 2
Bank 3
BANK