s3c72m9 Samsung Semiconductor, Inc., s3c72m9 Datasheet - Page 44

• Manufacturer Part Number: s3c72m9
• Description: The S3c72m5/s3c72m7/s3c72m9 Single-chip Cmos Microcontroller Has Been Designed For High Performance Using Samsung S
• Manufacturer: Samsung Semiconductor, Inc.

ADDRESSING MODES
ENABLE MEMORY BANK SETTINGS
EMB = "1"
When the enable memory bank flag EMB is set to logic one, you can address the data memory bank specified by
the select memory bank (SMB) value (0, 1–13, 14, or 15) using 1-, 4-, or 8-bit instructions. You can use both direct
and indirect addressing modes. The addressable RAM areas when EMB = "1" are as follows:
If SMB = 0,
If SMB = 1,
If SMB = 2,
If SMB = 15,
EMB = "0"
When the enable memory bank flag EMB is set to logic zero, the addressable area is defined independently of the
SMB value, and is restricted to specific locations depending on whether a direct or indirect address mode is used.
If EMB = "0", the addressable area is restricted to locations 000H–07FH in bank 0 and to locations F80H–FFFH in
bank 15 for direct addressing. For indirect addressing, only locations 000H–0FFH in bank 0 are addressable,
regardless of SMB value.
To address the peripheral hardware register (bank 15) using indirect addressing, the EMB flag must first be set to "1"
and the SMB value to "15". When a RESET occurs, the EMB flag is set to the value contained in bit 7 of ROM
address 0000H.
EMB-Independent Addressing
At any time, several areas of the data memory can be addressed independent of the current status of the EMB flag.
These exceptions are described in Table 3-1.
3-4
•
•
•
FB0H–FBFH
FF0H–FFFH
FC0H–FFFH
000H–0FFH
Address
000H–0FFH
100H–1FFH
200H–2FFH
F80H–FFFH
4-bit indirect addressing using WX
and WL register pairs;
8-bit indirect addressing using SP
1-bit direct addressing
1-bit indirect addressing using the
L register
•
•
•
Table 3-1. RAM Addressing Not Affected by the EMB Value
Addressing Method
Not applicable
PSW, SCMOD,
IEx, IRQx, I/O
BSC, I/O
Affected Hardware
S3C72M5/C72M7/C72M9/P72M9 (Preliminary Spec)
LD
PUSH
POP
BITS
BITR
BTST
BAND C,P3.@L
Program Examples
FC3H.@L
EMB
A,@WX
IE4