58 Dialog Semiconductor Plc | Annual report and accounts 2012  |  Section 4 | Consolidated financial statements and notes Consolidated statement of cash flows For the year ended 31 December 2012  Notes 2012  US$000  2011 US$000 Cash flows from operating activities: Net profit  62,513  57,352 Adjustments to reconcile net profit to net cash used for operating activities :  Interest income, net  3 5,106  (141) Income tax expense  5 23,612  4,070 Impairment of inventories  8,207  3,660 Depreciation of property, plant and equipment  11 12,698  8,801 Amortisation of intangible assets  12 19,593  16,030 Losses on disposals of fixed assets and impairment of fixed and financial assets  1,029  1,106 Expense related to share-based payments  21 6,955  6,329 Changes in working capital:  Trade accounts receivable, other receivables and factoring  7 (36,158) (21,451) Inventories  (105,015)  (10,716) Prepaid expenses  (159) (967) Trade accounts payable  55,652  11,958 Provisions  293  (334) Other assets and liabilities  7,462  (3,336) Cash generated from operations  61,788  72,361 Interest paid  (1,141) (109) Interest received  1,277  381 Income taxes paid  (9,483)  (3,078) Cash flow from operating activities  52,441  69,555 Cash flows from investing activities: Purchase of property, plant and equipment  11 (35,025) (21,161) Purchase of intangible assets  12 (13,417) (5,414) Payments for capitalised development costs  12 (5,956) (5,165) Purchase of SiTel Semiconductor B.V.  4 –  (84,166) Deposits received back (made)  98  (157) Cash flow used for investing activities  (54,300) (116,063) Cash flows from financing activities: Cash flow from the convertible bond  196,631  – Sale of employee stock purchase plan shares 4,114  2,254 Cash flow from financing activities  200,745  2,254 Cash flow from (used for) operating, investing and financing activities  198,886  (44,254) Net foreign exchange difference  (41) (356) Net increase (decrease) in cash and cash equivalents  198,845  (44,610) Cash and cash equivalents at beginning of period  113,590  158,200 Cash and cash equivalents at end of period  6 312,435  113,590