Using fewer bytes to store data - 8051 - memory

Question

I'm currently working on code for the 8051 processor, and I'm trying to figure out better ways to store data in immediate RAM without using so many bytes of rom space. The data is mostly random but sometimes some data is null.
For example, I have a device connected to my chip that expects 7 bytes of data for processing. Let's say I want to send to that device the following data:
12h 34h 56h 41h 33h 77h 00h
The quick way for me to do this is something like the following:
DATABLOCK equ 30h
MOV DATABLOCK,#12h
MOV DATABLOCK+1,#34h
MOV DATABLOCK+2,#56h
MOV DATABLOCK+3,#41h
MOV DATABLOCK+4,#33h
MOV DATABLOCK+5,#77h
MOV DATABLOCK+6,#00h
I refer to the following website for instructions:
http://www.keil.com/support/man/docs/is51/is51_mov.htm
and based on my code, I needed 21 bytes to store that in rom. One byte for MOV, one byte for destination (DATABLOCK+x) and one byte for the value (xxh). multiply total by 7 = 21.
The problem is, I use this kind of command frequently because its fast but I have limited free space on the chip.
I thought of the following but it doesn't really help. Heck, I think it takes an EXTRA two bytes:
DATABLOCK equ 30h
MOV R0,#DATABLOCK
MOV #R0,#12h
INC R0
MOV #R0,#34h
INC R0
MOV #R0,#56h
INC R0
MOV #R0,#41h
INC R0
MOV #R0,#33h
INC R0
MOV #R0,#77h
INC R0
MOV #R0,#00h
And then I thought of this which can get crazy which I think takes even MORE bytes:
DATABLOCK equ 30h
mov R1,SP
MOV SP,#DATABLOCK-1
MOV A,#12h
PUSH ACC
MOV A,#34h
PUSH ACC
MOV A,#56h
PUSH ACC
MOV A,#41h
PUSH ACC
MOV A,#33h
PUSH ACC
MOV A,#77h
PUSH ACC
MOV A,#00h ;could use CLR A but what if value isn't 0h?
PUSH ACC
MOV SP,R1
Now the problem is I don't have that much ram either so I can't afford to keep the same values in ram for the entire program. If I could, I would implement code like this:
FIND12H equ 70h
FIND34H equ 60h
FIND56H equ 50h
FIND41H equ 55h
FIND33H equ 66h
FIND77H equ 22h
FIND00H equ 2Ah
DATABLOCK equ 30h
mov R1,SP
MOV SP,#DATABLOCK-1
PUSH FIND12H
PUSH FIND34H
PUSH FIND56H
PUSH FIND41H
PUSH FIND33H
PUSH FIND77H
PUSH FIND00H
MOV SP,R1
Now that code there would only cost me maybe 12 bytes. That's a savings of about 9 bytes (like over 1/3), but the problem is I'm using absolute values, not memory locations. Like if the following worked with the 8051, then my question would be answered:
mov A,SP
MOV SP,#DATABLOCK-1
PUSH #12h
PUSH #34h
PUSH #56h
PUSH #41h
PUSH #33h
PUSH #77h
PUSH #0h
MOV SP,A
But for the push command, the parameter cannot be a hard-coded value.
So given what all I have presented, How can I use fewer rom bytes to store data into internal memory?

Answer 1

"For example, I have a device connected to my chip that expects 7 bytes of data for processing" Why you need the data in RAM? You can copy the data right from ROM. For example if you want to send data via UART (not checked if work):
sendData:
MOV DPTR, constData ;pointer to data in ROM
MOV R0, #7 ;number of data to send
sendMore:
MOVC A, #DPTR ;move data to accumulator
MOV SBUF, A ;send data via UART
JNB TI, $ ;wait for TI flag
CLR TI ;clear TI flag
INC DPTR ;increment pointer
DJNZ R0, sendMore ;decrement couter and jump if not zero
constData: DB #12h, #34h, #56h, #41h, #33h, #77h, #00h ;constants stored in ROM
If you really want the data in RAM you can use memory copy function which looks something like this:
ARRAY_START equ 30h
ARRAY_LEN equ 7h
MOV R0, ARRAY_START ;set pointer to start array
MOV DPTR, SrcTable ;pointer to data in ROM
copyMore:
MOVC A, #DPTR ;move data to acumulator
MOV #R0, A ;move data to RAM destination
INC DPTR ;increment source pointer
INC R0 ;increment destination pointer
CJNE R0, ARRAY_START+ARRAY_LEN, copyMore
SrcTable: DB #12h, #34h, #56h, #41h, #33h, #77h, #00h ;constants stored in ROM