Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
SST89E58RD2-33-C-PI Datasheet(PDF) 13 Page - Silicon Storage Technology, Inc |
|
SST89E58RD2-33-C-PI Datasheet(HTML) 13 Page - Silicon Storage Technology, Inc |
13 / 81 page Data Sheet FlashFlex51 MCU SST89E52RD2/RD / SST89E54RD2/RD / SST89E58RD2/RD SST89V52RD2/RD / SST89V54RD2/RD / SST89V58RD2/RD 13 ©2006 Silicon Storage Technology, Inc. S71255-05-000 5/06 3.2 Program Memory Block Switching The program memory block switching feature of the device allows either Block 1 or the lowest 8 KByte of Block 0 to be used for the lowest 8 KByte of the program address space. SFCF[1:0] controls program memory block switching. 3.2.1 Reset Configuration of Program Memory Block Switching Program memory block switching is initialized after reset according to the state of the Start-up Configuration bit SC0 and/or SC1. The SC0 and SC1 bits are programmed via an external host mode command or an IAP Mode com- mand. See Table 4-2. Once out of reset, the SFCF[0] bit can be changed dynam- ically by the program for desired effects. Changing SFCF[0] will not change the SC0 bit. Caution must be taken when dynamically changing the SFCF[0] bit. Since this will cause different physical memory to be mapped to the logical program address space. The user must avoid executing block switching instructions within the address range 0000H to 1FFFH. 3.3 Data RAM Memory The data RAM has 1024 bytes of internal memory. The RAM can be addressed up to 64KB for external data memory. 3.4 Expanded Data RAM Addressing The SST89E/V5xRDx both have the capability of 1K of RAM. See Figure 3-4. The device has four sections of internal data memory: 1. The lower 128 Bytes of RAM (00H to 7FH) are directly and indirectly addressable. 2. The higher 128 Bytes of RAM (80H to FFH) are indirectly addressable. 3. The special function registers (80H to FFH) are directly addressable only. 4. The expanded RAM of 768 Bytes (00H to 2FFH) is indirectly addressable by the move external instruction (MOVX) and clearing the EXTRAM bit. (See “Auxiliary Register (AUXR)” in Section 3.6, “Special Function Registers”) Since the upper 128 bytes occupy the same addresses as the SFRs, the RAM must be accessed indirectly. The RAM and SFRs space are physically separate even though they have the same addresses. When instructions access addresses in the upper 128 bytes (above 7FH), the MCU determines whether to access the SFRs or RAM by the type of instruction given. If it is indirect, then RAM is accessed. If it is direct, then an SFR is accessed. See the examples below. TABLE 3-1: SFCF Values for Program Memory Block Switching SFCF[1:0] Program Memory Block Switching 10, 11 Block 1 is not visible to the PC; Block 1 is reachable only via in-application programming from E000H - FFFFH. 01 Both Block 0 and Block 1 are visible to the PC. Block 0 is occupied from 0000H - 7FFFH. Block 1 is occupied from E000H - FFFFH. 00 Block 1 is overlaid onto the low 8K of the program address space; occupying address locations 0000H - 1FFFH. When the PC falls within 0000H - 1FFFH, the instruction will be fetched from Block 1 instead of Block 0. Outside of 0000H - 1FFFH, Block 0 is used. Locations 0000H - 1FFFH of Block 0 are reachable through in-application programming. T3-1.0 1255 TABLE 3-2: SFCF Values Under Different Reset Conditions SC11 1. P = Programmed (Bit logic state = 0), U = Unprogrammed (Bit logic state = 1) SC01 State of SFCF[1:0] after: Power-on or External Reset WDT Reset or Brown-out Reset Software Reset U (1) U (1) 00 (default) x0 10 U (1) P (0) 01 x1 11 P (0) U (1) 10 10 10 P (0) P (0) 11 11 11 T3-2.0 1255 |
Número de pieza similar - SST89E58RD2-33-C-PI |
|
Descripción similar - SST89E58RD2-33-C-PI |
|
|
Enlace URL |
Política de Privacidad |
ALLDATASHEET.ES |
¿ALLDATASHEET es útil para Ud.? [ DONATE ] |
Todo acerca de Alldatasheet | Publicidad | Contáctenos | Política de Privacidad | Intercambio de Enlaces | Lista de Fabricantes All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |