HP 3000 III Series Manual page 214

Label and Name
System Microcode
Table 5-8. MCU Option Field Code Definitions
1------
-----------1----·-1------·----------------------------
I
1
Fie ld
1 1
1
Code
1
Des cr ipt ion
1
________________ 1 - 1 - . 1
ABS
(Absolu te)
CMD
(Command)
CRL
(Control)
DATA
DB
(DB-Relative)
00000
00010
00001
10001
10000
The MCU option code ABS specifies
the ABS Registe r which may be read
into S-Bus (12: 15) wi th "RBR" or
stored from U-Bus (12:15) with
"SBR". This bank register is used
as a scratch pad bank register by
the micr ocode •
The MCU option code CMD enables the
bus options (BUS, BSPO, and BSPl)
in the Store field to store the U-
Bus into the address CPU output
register, ACOR, and to initiate a
lew-request command. When selected,
the AOOR is outputed to the MCU-Bus
and the command and module number
("TO" lines) are obtained from the
TO and MOP Registers.
The MCU option code CRL enables the
Store field bus options (BUS, BSPO,
and BSPl) to load the TO and MOP
Registers from the U-Bus.
MOP(O:l) := U-BUS(lO:ll) Command
TO(2:4)
:=
U-BUS(13:l5) Address
The MOP Registe r then con ta ins a
user defined command for the module
whose address is contained in the
TO Register. The CPU freezes until
any pending MCU requests are com-
pIe ted.
The MCU option code DATA enables
Store field bus options (as in CRL)
to store the U-Bus into beOR and to
initiate a high-request command.
The MCU option code DB functions
the same as ABS except that it
specifies the DB-Bank Register used
with DB-relative addressing.
5-34