STARTUP.A51详解

Name

Description

IDATALEN

Specifies the number of bytes of idata to clear to 0. The default is 80h because most 8051 derivatives contain at least 128 bytes of internal data memory. Use a value of 100h for the 8052 and other derivatives that have 256 bytes of internal data memory.

XDATASTART

Specifies the initial xdata address to clear to 0.

XDATALEN

Indicates the number of bytes of xdata to clear to 0. The default is 0.

PDATASTART

Specifies the initial pdata address to clear to 0.

PDATALEN

Specifies the number of bytes of pdata to clear to 0. The default is 0.

IBPSTACK

Specifies whether or not the small model reentrant stack pointer (?C_IBP) should be initialized. A value of 1 causes this pointer to be initialized. A value of 0 prevents initialization of this pointer. The default is 0.

IBPSTACKTOP

Specifies the top of the small model reentrant stack. The default is 0xFF in idata memory. The Cx51 Compiler does not check to see if the stack area available satisfies the requirements of the application. It is your responsibility to perform such a test.

XBPSTACK

Specifies whether or not the large model reentrant stack pointer (?C_XBP) should be initialized. A value of 1 causes this pointer to be initialized. A value of 0 prevents initialization of this pointer. The default is 0.

XBPSTACKTOP

Specifies the top of the large model reentrant stack. The default is 0xFFFF in xdata memory. The Cx51 Compiler does not check to see if the stack area available satisfies the requirements of the application. It is your responsibility to perform such a test.

PBPSTACK

Specifies whether the compact model reentrant stack pointer (?C_PBP) should be initialized. A value of 1 causes this pointer to be initialized. A value of 0 prevents initialization of this pointer. The default is 0.

PBPSTACKTOP

Specifies the top of the compact model reentrant stack. The default is 0xFF in pdata memory. The Cx51 Compiler does not check to see if the stack area available satisfies the requirements of the application. It is your responsibility to perform such a test.

PPAGEENABLE

Enables (a value of 1) or disables (a value of 0) Port 2 initialization for pdata memory access. The default is 0. pdata addressing uses Port 2 for the upper address (or page) byte.

PPAGE

Specifies the value to write to Port 2 of the 8051 for pdata memory access. This value represents the xdata memory page to use for pdata. This is the upper 8 bits of the absolute address range to use for pdata. For example, if the pdata area begins at address 1000h (page 10h) in xdata memory, PPAGEENABLE should be set to 1, and PPAGEshould be set to 10h. You must specify the starting pdata address to use to the BL51 Linker using the PDATA directive. For example:

BL51 input modules PDATA (1050H)

Neither the BL51 Linker nor the Cx51 Compiler checks to see if the PDATA directive and the PPAGE startup constant are correctly specified. You must ensure that these parameters contain suitable values.