MON51 User's Guide

MON_BANK.A51

When you install Monitor-51 for code banking, you must specify the number of code banks your hardware provides as well as how the code banks are switched. This is done by changing constants defined in the assembly module MON_BANK.A51.

MON_BANK.A51 Constants

The banking method as well as the number of banks and thus the number of address lines used are configured using this source file. MON_BANK.A51 contains EQU statements at the beginning which are used for the configuration. Following is a listing of these as well as a description of each.

;************************ Configuration Section ****************************
?B_NBANKS       EQU     8        ; Define max. Number of Code Banks (not   *
;                                ; including XDATA or COMMON bank).        *
;                                ; The max. value for ?B_BANKS is 32       *
;                                ; possible values are: 1,2,3,...32        *
;                                                                          *
?B_MODE         EQU     0        ; 0 for Bank-Switching via 8051 Port      *
;                                ; 1 for Bank-Switching via XDATA Port     *
;                                                                          *
?B_BANKSTART    EQU     08000H   ; defines the start address of the code   *
;                                ; banking area                            *
;                                                                          *
?B_BANKEND      EQU     0FFFFH   ; defines the end address of the code     *
;                                ; banking area                            *
;                                                                          *
?B_COMMON       EQU     0FFH     ; 0FFH if the COMMON area is not mapped   *
;                                ; into a code bank, otherwise             *
;                                ; ?B_COMMON must be set to the bank       *
;                                ; number which contains the COMMON area   *
;                                                                          *
?B_XRAM         EQU     0FFH     ; 0FFH if the XDATA RAM area is not       *
;                                ; mapped into a code bank, otherwise      *
;                                ; ?B_XRAM must be set to the bank number  *
;                                ; which contains the XDATA RAM area       *
;                                                                          *
?B_MON_DATA_BANK EQU    007H     ; Bank number where monitor data is       *
;                                ; stored.                                 *
;                                                                          *
IF ?B_MODE = 0;                                                            *
;--------------------------------------------------------------------------*
; if ?BANK?MODE is 0 define the following values                           *
; For Bank-Switching via 8051 Port define Port Address / Bits              *
?B_PORT         EQU     P1      ; default is P6                            *
?B_FIRSTBIT     EQU     0       ; default is Bit 5                         *
;--------------------------------------------------------------------------*

• ?B_NBANKS indicates the number of banks to be supported. The number must be between 2 and 32. Only one 8051 address line (port terminal) is used for two banks. Three or four banks require two address lines. Five to eight banks require three address lines. Nine to sixteen banks require four address lines. Seventeen to thirty-two banks require five address lines.
• ?B_MODE indicates if the bank switching code should use an 8051 port or an XDATA port for the address extension. A value of 0 defines an arbitrary 8051 port for the address extension. A value of 1 determines a XDATA port which is addressed in the external address space of the 8051.
• ?B_BANKSTART specifies the start address of the banking area. The value 0 means, that there is no physical common area. In this case, the logical common area is automatically copied into every code bank during the load process of your application. The value 0FFFFH specifies, that you are running a banked version of Monitor-51 on a non-banked hardware. 8000H is defined as the default value.
• ?B_BANKEND specifies the end address of the banking area. This value must be greater or equal than ?B_BANKSTART. 0FFFFH is defined as the default value.
• ?B_COMMON indicates whether the physical common area must be accessed as a bank or not. The default value 0FFH specifies, that the common area is not mapped to a bank. Any other value specifies the bank number of the common area. This option is used to separate the common area and XDATA area, although the common area is 'von Neumann' mapped.
• ?B_XRAM indicates whether the XDATA area must be accessed as a bank or not. The default value 0FFH specifies, that the XDATA area is not mapped to a bank. Any other value specifies the bank number of the XDATA area. This option is used to separate the common and XDATA area. Both, ?B_COMMON and ?B_XRAM have to be set to 0FFH or both to different values.
• ?B_MON_DATA_BANK specifies the bank number of the XDATA area used by Monitor-51. In order to save memory space, the 256 byte monitor XDATA area and the optional 5KB trace memory can be located in a code bank instead of the commonarea.
• ?B_PORT specifies the port address used to select the bank address. If the value 0 is used for ?B_MODE, ?B_PORT can be used to specify the address of the internal data port. In this case, the SFT address of an internal data port must be specified. P1 is defined as the default value for port 1.
• ?B_XDATAPORT specifies the XDATA memory address used to select the bank address. If the value 1 is used for ?B_MODE, ?B_XDATAPORT defines the address an external data port. In this case, an arbitrary XDATA address can be specified (address range 0H to 0FFFFH) under which a port can be addressed in the XDATA area. 0FFFFH is defined as the default value.
• ?B_FIRSTBIT indicates which bit of the defined port is to be assigned first. The value ?B_FIRSTBIT EQU 3 (defined as the default when ?B_MODE is 0) indicates that P1.3 is to be used as the first port terminal for the address extension. If, for example two port terminals are used for the extension, P1.3 and P1.4 are used in this case. The remaining lines of the 8051 port can be used for other purposes. If the value 1 is selected for ?B_MODE, remaining bits of the XDATA port cannot be used for other purposes.