
CHAPTER 12 NBD FUNCTION (
μ
PD70F3116)
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User’s Manual U14492EJ5V0UD
(2) Access to NBD space
The following are the commands for reading or writing to the NBD space from the NBD tool. For the NBD
space, the access address length is fixed to 12 bits and the access data length is fixed to 8 bits.
(a) Write command
The address (NBD space address: 12 bits) at which write to the NBD space is to be performed and the
data sent from the NBD tool are received as a command packet. After receiving the command packet
shown in Table 12-6 from the NBD tool, a Ready command is output following write completion.
Command packets can be received once more from the NBD tool (after Ready command SYNC inactive
confirmation).
Table 12-6. Command Packet (Write Access to NBD Space)
ADn_DBG
AD3_DBG
AD2_DBG
AD1_DBG
AD0_DBG
1st
0
0
0
0
2nd
0
0
1
0
3rd
A3
A2
A1
A0
4th
A7
A6
A5
A4
5th
A11
A10
A9
A8
6th
D3
D2
D1
D0
7th
D7
D6
D5
D4
Caution The length of an NBD space write address is fixed to 12 bits.
The length of the write data is fixed to 8 bits.
(b) Read command
The target address (real address of target: 12 bits), at which read of internal RAM is to be performed,
which is sent from the NBD tool, is received 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.
Table 12-7. Command Packet (Read Access to NBD Space)
ADn_DBG
AD3_DBG
AD2_DBG
AD1_DBG
AD0_DBG
1st
0
0
0
0
2nd
0
0
0
0
3rd
A3
A2
A1
A0
4th
A7
A6
A5
A4
5th
A11
A10
A9
A8
Caution The length of an NBD space read address is fixed to 12 bits.
In read mode, the output data section from the NBD tool is deleted.