EZ80L92MCU Datasheet, PDF (189/241 Pages) Zilog, Inc. – eZ80Acclaim Flash Microcontrollers

eZ80L92 MCU
Product Specification
174
ZDI Read/Write Control Register
The ZDI Read/Write Control register is used in the ZDI Write-Only Register address to
read data from, write data to, and manipulate the CPU’s registers or memory locations.
When this register is written, the eZ80L92 immediately performs the operation corre-
sponding to the data value written as described in Table 96. When a Read operation is exe-
cuted via this register, the requested data values are placed in the ZDI Read Data registers
{ZDI_RD_U, ZDI_RD_H, ZDI_RD_L}. When a Write operation is executed via this reg-
ister, the Write data is taken from the ZDI Write Data registers {ZDI_WR_U,
ZDI_WR_H, ZDI_WR_L}. See Table 96. Refer to the eZ80 CPU User Manual (UM0077)
for information regarding the CPU registers.
Table 96. ZDI Read/Write Control Register Functions (ZDI_RW_CTL = 16h in the ZDI
Register Write-Only Address Space)
Hex
Value
Command
Hex
Value
Command
00
Read {MBASE, A, F}
80
Write {MBASE, A, F}
ZDI_RD_U ← MBASE
MBASE ← ZDI_WR_U
ZDI_RD_H ← F
F ← ZDI_WR_H
ZDI_RD_L ← A
A ← ZDI_WR_L
01
Read BC
ZDI_RD_U ← BCU
ZDI_RD_H ← B
ZDI_RD_L ← C
81
Write BC
BCU ← ZDI_WR_U
B ← ZDI_WR_H
C ← ZDI_WR_L
02
Read DE
ZDI_RD_U ← DEU
ZDI_RD_H ← D
ZDI_RD_L ← E
82
Write DE
DEU ← ZDI_WR_U
D ← ZDI_WR_H
E ← ZDI_WR_L
03
Read HL
ZDI_RD_U ← HLU
ZDI_RD_H ← H
ZDI_RD_L ← L
83
Write HL
HLU ← ZDI_WR_U
H ← ZDI_WR_H
L ← ZDI_WR_L
04
Read IX
ZDI_RD_U ← IXU
ZDI_RD_H ← IXH
ZDI_RD_L ← IXL
84
Write IX
IXU ← ZDI_WR_U
IXH ← ZDI_WR_H
IXL ← ZDI_WR_L
05
Read IY
ZDI_RD_U ← IYU
ZDI_RD_H ← IYH
ZDI_RD_L ← IYL
85
Write IY
IYU ← ZDI_WR_U
IYH ← ZDI_WR_H
IYL ← ZDI_WR_L
Note: The eZ80^® CPU’s alternate register set (A’, F’, B’, C’, D’, E’, HL’) cannot be read directly. The
ZDI programmer must execute the exchange instruction (EXX) to gain access to the alternate
eZ80^® CPU register set.
PS013012-1004
PRELIMINARY
ZiLOG Debug Interface