CHAPTER 12 NBD FUNCTION (
µµµµ
PD70F3116)
632
User’s Manual U14492EJ3V0UD
12.4 NBD Function
12.4.1 RAM monitoring, accessing NBD space
The NBD function performs read and write operations on internal RAM data via DMA (direct memory access) for
addresses in internal RAM. It also performs reading or writing to NBD space.
(1) RAM monitoring
The following are the commands for reading and writing to internal RAM areas from the NBD tool.
(a) Write command
The target address (real address of target: lower 24 bits) at which a write to internal RAM is to be made
and the data are received from the NBD tool as a command packet. After receiving the command packet
shown below from the NBD tool, a Ready command is output following write termination.
Command packets can be received once more from the NBD tool (after Ready command SYNC inactive
confirmation).
Table 12-3. Command Packet (On a Write)
ADn_DBG
AD3_DBG
AD2_DBG
AD1_DBG
AD0_DBG
1st
0
0
0
0
2nd
SIZ1
SIZ0
1
1
3rd to 8th
Target space write address specification (24 bits)
9th to 16th
Write data (data specified by SIZ0 and SIZ1)
(b) Read command
The target address (real address of target: lower 24 bits) at which a read of internal RAM is to be made is
received from the NBD tool as a command packet. After receiving the command packet from the NBD
tool, a Ready command is output, SYNC is made inactive, and the data at the address specified by the
command packet is transmitted to the NBD tool. The address (A27 to A24) during read is “1111”.
Table 12-4. Command Packet (On a Read)
ADn_DBG
AD3_DBG
AD2_DBG
AD1_DBG
AD0_DBG
1st
0
0
0
0
2nd
SIZ1
SIZ0
0
1
3rd to 8th
Target space read address specification (24 bits)
Caution
In read mode, the output data section from the NBD tool is deleted.
Table 12-5. Data Packet (On a Read)
ADn_DBG
AD3_DBG
AD2_DBG
AD1_DBG
AD0_DBG
1st to 8th
Target space read data
Содержание V850E/IA1 mPD703116
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