Philips CEM2100/00, Service Manual

Page: 355 / 430

Page 233
T
5CL8
20. Serial PROM Mode
20.1 Outline
The T
5CL8
has a 2048 byte BOOTROM (Mask ROM) for programming to flash memory. The
BOOTROM is available in the serial PROM mode, and controlled by TEST, BOOT and
RESET
pins. Communica-
tion is performed via UART. The serial PROM mode has seven types of operating mode: Flash memory writing,
RAM loader, Flash memory SUM output, Product ID code output, Flash memory status output, Flash memory eras-
ing and Flash memory security program setting. Memory address mapping in the serial PROM mode differs from
that in the MCU mode. Figure 20-1 shows memory address mapping in the serial PROM mode.
Note: Though included in above operating range, some of high frequencies are not supported in the serial PROM mode. For
details, refer to “Table 20-5”.
20.2 Memory Mapping
The Figure 20-1 shows memory mapping in the Serial PROM mode and MCU mode.
In the serial PROM mode, the BOOTROM (Mask ROM) is mapped in addresses from 7800H to 7FFFH. The flash
memory is divided into two banks for mapping. Therefore, when the RAM loader mode (60H) is used, it is required
to specify the flash memory address according to Figure 20-1 (For detail of banks and control register, refer to the
chapter of “Flash Memory Control Register”.)
Figure 20-1 Memory Address Maps
Table 20-1 Operating Range in the Serial PROM Mode
Parameter Min Max Unit
Power supply 4.5 5.5 V
High frequency (Note) 2 16 MHz
To use the Flash memory writing command (30H), specify the flash memory addresses from 1000H to FFFFH, that
is the same addresses in the MCU mode, because the BOOTROM changes the flash memory address.
003FH
0000H
64 bytes
2048 bytes
0040H
0FFFH
7800H
7FFFH
8000H 8000H
7FFFH
FFFFH FFFFH
SFR
RAM
DBR
SFR
RAM
DBR
BOOTROM
Flash memory
Serial PROM mode MCU mode
9000H
28672 bytes
(BANK0)
32768 bytes
(BANK1)
61440 bytes
003FH
0000H
64 bytes
0040H
0FFFH
1000H
Flash memory
2048 bytes
128 bytes 128 bytes
083FH
0F80H
0F80H
2048 bytes
083FH