Diff: lenval.h
- Revision:
- 0:1be76329b246
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/lenval.h Sat Jun 30 13:17:05 2012 +0000
@@ -0,0 +1,93 @@
+/*******************************************************/
+/* file: lenval.h */
+/* abstract: This file contains a description of the */
+/* data structure "lenval". */
+/*******************************************************/
+
+#ifndef lenval_dot_h
+#define lenval_dot_h
+
+/* the lenVal structure is a byte oriented type used to store an */
+/* arbitrary length binary value. As an example, the hex value */
+/* 0x0e3d is represented as a lenVal with len=2 (since 2 bytes */
+/* and val[0]=0e and val[1]=3d. val[2-MAX_LEN] are undefined */
+
+/* maximum length (in bytes) of value to read in */
+/* this needs to be at least 4, and longer than the */
+/* length of the longest SDR instruction. If there is, */
+/* only 1 device in the chain, MAX_LEN must be at least */
+/* ceil(27/8) == 4. For 6 devices in a chain, MAX_LEN */
+/* must be 5, for 14 devices MAX_LEN must be 6, for 20 */
+/* devices MAX_LEN must be 7, etc.. */
+/* You can safely set MAX_LEN to a smaller number if you*/
+/* know how many devices will be in your chain. */
+/* #define MAX_LEN (Actual #define is below this comment block)
+ This #define defines the maximum length (in bytes) of predefined
+ buffers in which the XSVF player stores the current shift data.
+ This length must be greater than the longest shift length (in bytes)
+ in the XSVF files that will be processed. 7000 is a very conservative
+ number. The buffers are stored on the stack and if you have limited
+ stack space, you may decrease the MAX_LEN value.
+
+ How to find the "shift length" in bits?
+ Look at the ASCII version of the XSVF (generated with the -a option
+ for the SVF2XSVF translator) and search for the XSDRSIZE command
+ with the biggest parameter. XSDRSIZE is equivalent to the SVF's
+ SDR length plus the lengths of applicable HDR and TDR commands.
+ Remember that the MAX_LEN is defined in bytes. Therefore, the
+ minimum MAX_LEN = ceil( max( XSDRSIZE ) / 8 );
+
+ The following MAX_LEN values have been tested and provide relatively
+ good margin for the corresponding devices:
+
+ DEVICE MAX_LEN Resulting Shift Length Max (in bits)
+ --------- ------- ----------------------------------------------
+ XC9500/XL/XV 32 256
+
+ CoolRunner/II 256 2048 - actual max 1 device = 1035 bits
+
+ FPGA 128 1024 - svf2xsvf -rlen 1024
+
+ XC18V00/XCF00
+ 1100 8800 - no blank check performed (default)
+ - actual max 1 device = 8192 bits verify
+ - max 1 device = 4096 bits program-only
+
+ XC18V00/XCF00 when using the optional Blank Check operation
+ 2500 20000 - required for blank check
+ - blank check max 1 device = 16384 bits
+*/
+#define MAX_LEN 7000
+
+
+typedef struct var_len_byte
+{
+ short len; /* number of chars in this value */
+ unsigned char val[MAX_LEN+1]; /* bytes of data */
+} lenVal;
+
+
+/* return the long representation of a lenVal */
+extern long value(lenVal *x);
+
+/* set lenVal equal to value */
+extern void initLenVal(lenVal *x, long value);
+
+/* check if expected equals actual (taking the mask into account) */
+extern short EqualLenVal(lenVal *expected, lenVal *actual, lenVal *mask);
+
+/* add val1+val2 and put the result in resVal */
+extern void addVal(lenVal *resVal, lenVal *val1, lenVal *val2);
+
+/* return the (byte, bit) of lv (reading from left to right) */
+extern short RetBit(lenVal *lv, int byte, int bit);
+
+/* set the (byte, bit) of lv equal to val (e.g. SetBit("00000000",byte, 1)
+ equals "01000000" */
+extern void SetBit(lenVal *lv, int byte, int bit, short val);
+
+/* read from XSVF numBytes bytes of data into x */
+extern void readVal(lenVal *x, short numBytes);
+
+#endif
+
Paul Clarke