SM59R16A5/SM59R09A5/SM59R05A5
8-Bit Micro-controller
64KB/36KB/20KB with ISP Flash
& 2KB RAM embedded
3.2.2.
Data memory - higher 128 byte (80h to FFh)
The address 80h to FFh can be accessed by indirect addressing mode.
Address 80h to FFh is data area.
3.2.3.
Data memory - Expanded 2048 bytes ($0000 to $07FF)
From external address 0000h to 07FFh is the on-chip expanded SRAM area, total 2K Bytes. This area can be accessed
by external direct addressing mode (by instruction MOVX).
If the address of instruction MOVX @DPTR is larger then 07FFh, the SM59R16A5 will generate the external memory
control signal automatically.
The address space of instruction MOVX @Ri, i=0, 1 is determined by RCON [7:0] of special function register $86 RCON
(internal RAM control register). The default setting of RCON [7:0] is 00h (page0). One page of data RAM is 256 bytes.
When EMEN = 0, the internal 2K expanded RAM is enabled. If access memory space is more than 2K byte, the value of
RCON is sent to Port2 to access external RAM.
When EMEN = 1, the internal 2K expanded RAM is disabled. The value of RCON is invalid and high byte address is
decided by register context of Port2 register P2 [7:0].
MOVX @Ri, A
MOVX A,@Ri
EMEN = 0
EMEN = 1
0
≦
RCON[7:0]
≦
3
Addr [15:8] <= RCON[7:0]
Port2 [7:0] <= P2 [7:0]
4
≦
RCON [7:0]
≦
255
Port2 [7:0] <= RCON[7:0]
Port2 [7:0] <= P2 [7:0]
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M047
25
Ver.G SM59R16A5 01/2014
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
