UPD77111 NEC, UPD77111 Datasheet - Page 25

• Manufacturer Part Number: UPD77111
• Description: 16-BIT FIXED-POINT DIGITAL SIGNAL PROCESSORS
• Manufacturer: NEC

5.1.1 Self boot
on the boot parameter written to address 0x4000 of the Y data memory. Generally, with a mask ROM model
( PD77111 or 77112), this function is implemented by storing the instructions to be booted in the data ROM.
self boot can be executed from this external data area.
because this address is in RAM. Therefore, with the PD77110, the self boot mode cannot be selected on power
application, and host boot must be executed. This also applies when the PLL is initialized. By writing a boot
parameter to address 0x4000 or those that follow of the Y data memory, self boot can be executed when the RESET
signal is subsequently input (except the reset that initializes the PLL). In this case, however, the instructions to be
booted are only those at address 0x0200 through 0x0FFF of the instruction RAM.
5.1.2 Host boot
instruction RAM.
RAM from addresses 0x0200 through 0x0FFF. To boot up the instruction RAM from 0x4000 through 0xBFFF, host
reboot is used.
5.2 Reboot
particular, the PD77110 has a reboot function that boots up the instruction RAM from 0x4000 through 0xBFFF.
5.2.1 Self reboot
Self boot
Host boot
The boot-up ROM transfers the instruction code stored in the data memory space to the instruction RAM, based
In addition, the instructions to be booted can be also stored in an external data area in the form of flash ROM, and
With the
In this boot mode, a boot parameter and instruction code are obtained via the host interface, and transferred to the
With the PD77110, the host boot mode is used on power application. The boot instruction area is the instruction
By calling the next reboot entry from the program, the contents of the instruction RAM can be rewritten. In
The instruction codes stored in the data memory are transferred to the instruction RAM.
This boot mode cannot be used with the PD77110.
Set the following parameters and call the entry address of the corresponding reboot mode to execute self reboot.
• R7L : Number of instruction steps for rebooting
• DP3: First address of X memory in which instruction codes are stored (in the case of reboot from X memory),
• DP7: First address of instruction memory to be loaded (in the case of reboot from X memory), or first address
or first address of the instruction memory to be loaded (in the case of reboot from Y memory)
of X memory in which instruction codes are stored (in the case of reboot from Y memory)
PD77110, the value of address 0x4000 of the Y data memory is undefined on power application,
X memory
Y memory
Host reboot
Reboot Mode
Data Sheet U12801EJ4V0DS00
Word reboot
Byte reboot
Word reboot
Byte reboot
PD77110, 77111, 77112
0x5 ( PD77111, 77112)
0x6 ( PD77110)
Entry Address
0x2
0x4
0x1
0x3
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