eZ80L92 MCU
Product Specification
182
ZDI Read Memory Register
When a Read is executed from the ZDI Read Memory register, the ZLP12840 fetches the
data from the memory address currently pointed to by the program counter, PC; the pro-
gram counter is then incremented. In Z80 MEMORY mode, the memory address is
{MBASE, PC[15:0]}. In ADL MEMORY mode, the memory address is PC[23:0]. Refer
to the eZ80® CPU User Manual (UM0077) for more information regarding Z80 and ADL
MEMORY modes.
The program counter, PC, increments after each data Read. However, the ZDI register
address does not increment automatically when this register is accessed. As a result, the
ZDI master can read any number of data bytes out of memory through the ZDI Read
Memory register. See Table 106.
Table 106. ZDI Read Memory Register (ZDI_RD_MEM = 20h in the ZDI
Register Read-Only Address Space)
Bit
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
0
Reset
CPU Access
Note: R = Read-only.
R
R
R
R
R
R
R
R
Bit
Position
Value Description
[7:0]
zdi_rd_mem
00h–FFh 8-bit data read from the memory address indicated by
the CPU’s program counter. In Z80 MEMORY mode,
8-bit data is transferred out from address {MBASE,
PC[15:0]}. In ADL Memory mode, 8-bit data is
transferred out from address PC[23:0].
PS013015-0316
Zilog Debug Interface
ZILOG [ ZILOG, INC. ]
