PCD5003AH Philips Semiconductors, PCD5003AH Datasheet - Page 17

• Manufacturer Part Number: PCD5003AH
• Description: Enhanced Pager Decoder for POCSAG
• Manufacturer: Philips Semiconductors

Philips Semiconductors
7.25
All internal access to the PCD5003A takes place via the
I
SRAM and EEPROM have been memory mapped and are
accessed via an index register. Table 13 shows the index
addresses of all internal blocks.
Registers are addressed directly, while RAM and
EEPROM are addressed indirectly via address pointers
and I/O registers.
Remark: The EEPROM memory map is non-contiguous
and organized as a matrix. The EEPROM address pointer
contains both row and column indicators.
1999 Jan 08
2
handbook, full pagewidth
C-bus interface. For this purpose the internal registers,
Enhanced Pager Decoder for POCSAG
(a) Master writes to slave.
(b) Master reads from slave.
(c) Combined format (shown: write plus read).
Decoder I
(a)
(b)
(c)
S
2
C-bus access
SL. ADR.
S
S
FROM
MASTER
0 (write)
SLAVE ADDRESS
SLAVE ADDRESS
R/W
A
address
INDEX
index
FROM
SLAVE
0 (write)
1 (read)
R/W
R/W
A
Fig.8 Message types.
acknowledge
DATA
n bytes with
S = START condition
P = STOP condition
A
A
address
INDEX
17
index
A
DATA
Data written to read-only bits will be ignored. Values read
from write-only bits are undefined and must be ignored.
Each I
with its slave address, followed by the index address of the
memory element to be accessed. An I
message uses the last written index address as a data
source. The different I
Fig.8.
As a slave the PCD5003A cannot initiate bus transfers by
itself. To prevent an external controller from having to
monitor the operating status of the decoder, all important
events generate an external interrupt on output INT.
n bytes with acknowledge
S
A
SL. ADR.
change of direction
2
C-bus write message to the PCD5003A must start
A
DATA
A = Acknowledge
N = Not acknowledge
1 (read)
n bytes with acknowledge
R/W
DATA
A
A
2
C-bus message types are shown in
acknowledge
n bytes with
DATA
N
DATA
P
N
MLC250
Product specification
P
A
2
PCD5003A
C-bus read
P